diff --git a/app/code/Magento/Inventory/Controller/Adminhtml/Source/Edit.php b/app/code/Magento/Inventory/Controller/Adminhtml/Source/Edit.php
index bb02cab9badc..e240a8360017 100644
--- a/app/code/Magento/Inventory/Controller/Adminhtml/Source/Edit.php
+++ b/app/code/Magento/Inventory/Controller/Adminhtml/Source/Edit.php
@@ -49,9 +49,9 @@ public function __construct(
      */
     public function execute(): ResultInterface
     {
-        $sourceId = (int)$this->getRequest()->getParam(SourceInterface::SOURCE_ID);
+        $sourceCode = $this->getRequest()->getParam(SourceInterface::SOURCE_CODE);
         try {
-            $source = $this->sourceRepository->get($sourceId);
+            $source = $this->sourceRepository->get($sourceCode);
 
             /** @var Page $result */
             $result = $this->resultFactory->create(ResultFactory::TYPE_PAGE);
@@ -64,7 +64,7 @@ public function execute(): ResultInterface
             /** @var Redirect $result */
             $result = $this->resultRedirectFactory->create();
             $this->messageManager->addErrorMessage(
-                __('Source with id "%value" does not exist.', ['value' => $sourceId])
+                __('Source with source code "%value" does not exist.', ['value' => $sourceCode])
             );
             $result->setPath('*/*');
         }
diff --git a/app/code/Magento/Inventory/Controller/Adminhtml/Source/InlineEdit.php b/app/code/Magento/Inventory/Controller/Adminhtml/Source/InlineEdit.php
index e5609b0aaeee..006928d9d799 100644
--- a/app/code/Magento/Inventory/Controller/Adminhtml/Source/InlineEdit.php
+++ b/app/code/Magento/Inventory/Controller/Adminhtml/Source/InlineEdit.php
@@ -66,19 +66,19 @@ public function execute(): ResultInterface
         if ($request->isXmlHttpRequest() && $request->isPost() && $requestData) {
             foreach ($requestData as $itemData) {
                 try {
-                    $sourceId = (int)$itemData[SourceInterface::SOURCE_ID];
-                    $source = $this->sourceRepository->get($sourceId);
+                    $sourceCode = $itemData[SourceInterface::SOURCE_CODE];
+                    $source = $this->sourceRepository->get($sourceCode);
                     $this->dataObjectHelper->populateWithArray($source, $itemData, SourceInterface::class);
                     $this->sourceRepository->save($source);
                 } catch (NoSuchEntityException $e) {
                     $errorMessages[] = __(
                         '[ID: %value] The Source does not exist.',
-                        ['value' => $sourceId]
+                        ['value' => $sourceCode]
                     );
                 } catch (ValidationException $e) {
                     foreach ($e->getErrors() as $localizedError) {
                         $errorMessages[] = __('[ID: %value] %message', [
-                            'value' => $sourceId,
+                            'value' => $sourceCode,
                             'message' => $localizedError->getMessage()
                         ]);
                     }
@@ -86,7 +86,7 @@ public function execute(): ResultInterface
                     $errorMessages[] = __(
                         '[ID: %value] %message',
                         [
-                            'value' => $sourceId,
+                            'value' => $sourceCode,
                             'message' => $e->getMessage()
                         ]
                     );
diff --git a/app/code/Magento/Inventory/Controller/Adminhtml/Source/Save.php b/app/code/Magento/Inventory/Controller/Adminhtml/Source/Save.php
index 1e412a642049..6593818c1af9 100644
--- a/app/code/Magento/Inventory/Controller/Adminhtml/Source/Save.php
+++ b/app/code/Magento/Inventory/Controller/Adminhtml/Source/Save.php
@@ -69,22 +69,24 @@ public function execute(): ResultInterface
     {
         $resultRedirect = $this->resultRedirectFactory->create();
         $request = $this->getRequest();
-        $requestData = $request->getParams();
+        $requestData = $request->getPost()->toArray();
+
         if (!$request->isPost() || empty($requestData['general'])) {
             $this->messageManager->addErrorMessage(__('Wrong request.'));
             $this->processRedirectAfterFailureSave($resultRedirect);
-
             return $resultRedirect;
         }
 
+        $sourceCodeQueryParam = $request->getQuery(SourceInterface::SOURCE_CODE);
         try {
-            $sourceId = isset($requestData['general'][SourceInterface::SOURCE_ID])
-                ? (int)$requestData['general'][SourceInterface::SOURCE_ID]
-                : null;
-            $sourceId = $this->processSave($requestData, $sourceId);
+            $source = (null !== $sourceCodeQueryParam)
+                ? $this->sourceRepository->get($sourceCodeQueryParam)
+                : $this->sourceFactory->create();
+
+            $this->processSave($source, $requestData);
 
             $this->messageManager->addSuccessMessage(__('The Source has been saved.'));
-            $this->processRedirectAfterSuccessSave($resultRedirect, $sourceId);
+            $this->processRedirectAfterSuccessSave($resultRedirect, $source->getSourceCode());
         } catch (NoSuchEntityException $e) {
             $this->messageManager->addErrorMessage(__('The Source does not exist.'));
             $this->processRedirectAfterFailureSave($resultRedirect);
@@ -92,32 +94,24 @@ public function execute(): ResultInterface
             foreach ($e->getErrors() as $localizedError) {
                 $this->messageManager->addErrorMessage($localizedError->getMessage());
             }
-            $this->processRedirectAfterFailureSave($resultRedirect, $sourceId);
+            $this->processRedirectAfterFailureSave($resultRedirect, $sourceCodeQueryParam ?? $sourceCodeQueryParam);
         } catch (CouldNotSaveException $e) {
             $this->messageManager->addErrorMessage($e->getMessage());
-            $this->processRedirectAfterFailureSave($resultRedirect, $sourceId);
+            $this->processRedirectAfterFailureSave($resultRedirect, $sourceCodeQueryParam ?? $sourceCodeQueryParam);
         } catch (Exception $e) {
             $this->messageManager->addErrorMessage(__('Could not save Source.'));
-            $this->processRedirectAfterFailureSave($resultRedirect, $sourceId ?? null);
+            $this->processRedirectAfterFailureSave($resultRedirect, $sourceCodeQueryParam ?? $sourceCodeQueryParam);
         }
-
         return $resultRedirect;
     }
 
     /**
+     * @param SourceInterface $source
      * @param array $requestData
-     * @param int|null $sourceId
-     *
-     * @return int
+     * @return void
      */
-    private function processSave(array $requestData, int $sourceId = null): int
+    private function processSave(SourceInterface $source, array $requestData)
     {
-        if (null === $sourceId) {
-            /** @var SourceInterface $source */
-            $source = $this->sourceFactory->create();
-        } else {
-            $source = $this->sourceRepository->get($sourceId);
-        }
         $source = $this->sourceHydrator->hydrate($source, $requestData);
 
         $this->_eventManager->dispatch(
@@ -128,7 +122,7 @@ private function processSave(array $requestData, int $sourceId = null): int
             ]
         );
 
-        $sourceId = $this->sourceRepository->save($source);
+        $this->sourceRepository->save($source);
 
         $this->_eventManager->dispatch(
             'controller_action_inventory_source_save_after',
@@ -137,21 +131,18 @@ private function processSave(array $requestData, int $sourceId = null): int
                 'source' => $source,
             ]
         );
-
-        return $sourceId;
     }
 
     /**
      * @param Redirect $resultRedirect
-     * @param int $sourceId
-     *
+     * @param string $sourceCode
      * @return void
      */
-    private function processRedirectAfterSuccessSave(Redirect $resultRedirect, int $sourceId)
+    private function processRedirectAfterSuccessSave(Redirect $resultRedirect, string $sourceCode)
     {
         if ($this->getRequest()->getParam('back')) {
             $resultRedirect->setPath('*/*/edit', [
-                SourceInterface::SOURCE_ID => $sourceId,
+                SourceInterface::SOURCE_CODE => $sourceCode,
                 '_current' => true,
             ]);
         } elseif ($this->getRequest()->getParam('redirect_to_new')) {
@@ -165,17 +156,16 @@ private function processRedirectAfterSuccessSave(Redirect $resultRedirect, int $
 
     /**
      * @param Redirect $resultRedirect
-     * @param int|null $sourceId
-     *
+     * @param string|null $sourceCode
      * @return void
      */
-    private function processRedirectAfterFailureSave(Redirect $resultRedirect, int $sourceId = null)
+    private function processRedirectAfterFailureSave(Redirect $resultRedirect, string $sourceCode = null)
     {
-        if (null === $sourceId) {
+        if (null === $sourceCode) {
             $resultRedirect->setPath('*/*/new');
         } else {
             $resultRedirect->setPath('*/*/edit', [
-                SourceInterface::SOURCE_ID => $sourceId,
+                SourceInterface::SOURCE_CODE => $sourceCode,
                 '_current' => true,
             ]);
         }
diff --git a/app/code/Magento/Inventory/Controller/Adminhtml/Stock/StockSourceLinkProcessor.php b/app/code/Magento/Inventory/Controller/Adminhtml/Stock/StockSourceLinkProcessor.php
index 90e98aa73aa0..ece5f8ff0097 100644
--- a/app/code/Magento/Inventory/Controller/Adminhtml/Stock/StockSourceLinkProcessor.php
+++ b/app/code/Magento/Inventory/Controller/Adminhtml/Stock/StockSourceLinkProcessor.php
@@ -78,23 +78,23 @@ public function process(int $stockId, array $stockSourceLinksData)
         $this->validateStockSourceData($stockSourceLinksData);
 
         $assignedSources = $this->getAssignedSourcesForStock->execute($stockId);
-        $sourceIdsForSave = array_flip(array_column($stockSourceLinksData, StockSourceLink::SOURCE_ID));
-        $sourceIdsForDelete = [];
+        $sourceCodesForSave = array_flip(array_column($stockSourceLinksData, StockSourceLink::SOURCE_CODE));
+        $sourceCodesForDelete = [];
 
         foreach ($assignedSources as $assignedSource) {
-            if (array_key_exists($assignedSource->getSourceId(), $sourceIdsForSave)) {
-                unset($sourceIdsForSave[$assignedSource->getSourceId()]);
+            if (array_key_exists($assignedSource->getSourceCode(), $sourceCodesForSave)) {
+                unset($sourceCodesForSave[$assignedSource->getSourceCode()]);
             } else {
-                $sourceIdsForDelete[] = $assignedSource->getSourceId();
+                $sourceCodesForDelete[] = $assignedSource->getSourceCode();
             }
         }
 
-        if ($sourceIdsForSave) {
-            $this->assignSourcesToStock->execute(array_keys($sourceIdsForSave), $stockId);
+        if ($sourceCodesForSave) {
+            $this->assignSourcesToStock->execute(array_keys($sourceCodesForSave), $stockId);
         }
-        if ($sourceIdsForDelete) {
-            foreach ($sourceIdsForDelete as $sourceIdForDelete) {
-                $this->unassignSourceFromStock->execute((int) $sourceIdForDelete, $stockId);
+        if ($sourceCodesForDelete) {
+            foreach ($sourceCodesForDelete as $sourceCodeForDelete) {
+                $this->unassignSourceFromStock->execute($sourceCodeForDelete, $stockId);
             }
         }
     }
@@ -107,7 +107,7 @@ public function process(int $stockId, array $stockSourceLinksData)
     private function validateStockSourceData(array $stockSourceLinksData)
     {
         foreach ($stockSourceLinksData as $stockSourceLinkData) {
-            if (!isset($stockSourceLinkData[StockSourceLink::SOURCE_ID])) {
+            if (!isset($stockSourceLinkData[StockSourceLink::SOURCE_CODE])) {
                 throw new InputException(__('Wrong Stock to Source relation parameters given.'));
             }
         }
diff --git a/app/code/Magento/Inventory/Indexer/SelectBuilder.php b/app/code/Magento/Inventory/Indexer/SelectBuilder.php
index 6d5b54131822..938e8b48e837 100644
--- a/app/code/Magento/Inventory/Indexer/SelectBuilder.php
+++ b/app/code/Magento/Inventory/Indexer/SelectBuilder.php
@@ -51,11 +51,11 @@ public function execute($stockId): Select
 
         // find all enabled sources
         $select = $connection->select()
-            ->from($sourceTable, [SourceInterface::SOURCE_ID])
+            ->from($sourceTable, [SourceInterface::SOURCE_CODE])
             ->where(SourceInterface::ENABLED . ' = ?', 1);
-        $sourceIds = $connection->fetchCol($select);
+        $sourceCodes = $connection->fetchCol($select);
 
-        if (0 === count($sourceIds)) {
+        if (0 === count($sourceCodes)) {
             return $select;
         }
 
@@ -71,11 +71,15 @@ public function execute($stockId): Select
             )
             ->joinLeft(
                 ['stock_source_link' => $sourceStockLinkTable],
-                'source_item.' . SourceItemInterface::SOURCE_ID . ' = stock_source_link.' . StockSourceLink::SOURCE_ID,
+                sprintf(
+                    'source_item.%s = stock_source_link.%s',
+                    SourceItemInterface::SOURCE_CODE,
+                    StockSourceLink::SOURCE_CODE
+                ),
                 []
             )
             ->where('stock_source_link.' . StockSourceLink::STOCK_ID . ' = ?', $stockId)
-            ->where('stock_source_link.' . StockSourceLink::SOURCE_ID . ' IN (?)', $sourceIds)
+            ->where('stock_source_link.' . StockSourceLink::SOURCE_CODE . ' IN (?)', $sourceCodes)
             ->group([SourceItemInterface::SKU]);
         return $select;
     }
diff --git a/app/code/Magento/Inventory/Indexer/Source/GetAssignedStockIds.php b/app/code/Magento/Inventory/Indexer/Source/GetAssignedStockIds.php
index fb76d015bb3f..be873ff320a3 100644
--- a/app/code/Magento/Inventory/Indexer/Source/GetAssignedStockIds.php
+++ b/app/code/Magento/Inventory/Indexer/Source/GetAssignedStockIds.php
@@ -31,10 +31,10 @@ public function __construct(
     }
 
     /**
-     * @param int[] $sourceIds
+     * @param string[] $sourceCodes
      * @return int[]
      */
-    public function execute(array $sourceIds): array
+    public function execute(array $sourceCodes): array
     {
         $connection = $this->resourceConnection->getConnection();
         $sourceStockLinkTable = $this->resourceConnection->getTableName(
@@ -44,7 +44,7 @@ public function execute(array $sourceIds): array
         $select = $connection
             ->select()
             ->from($sourceStockLinkTable, StockSourceLink::STOCK_ID)
-            ->where(StockSourceLink::SOURCE_ID . ' IN (?)', $sourceIds)
+            ->where(StockSourceLink::SOURCE_CODE . ' IN (?)', $sourceCodes)
             ->group(StockSourceLink::STOCK_ID);
 
         $stockIds = $connection->fetchCol($select);
diff --git a/app/code/Magento/Inventory/Indexer/Source/SourceIndexer.php b/app/code/Magento/Inventory/Indexer/Source/SourceIndexer.php
index cede86e7585b..34fbe9b21a12 100644
--- a/app/code/Magento/Inventory/Indexer/Source/SourceIndexer.php
+++ b/app/code/Magento/Inventory/Indexer/Source/SourceIndexer.php
@@ -56,17 +56,17 @@ public function executeFull()
     /**
      * @inheritdoc
      */
-    public function executeRow($sourceId)
+    public function executeRow($sourceCode)
     {
-        $this->executeList([$sourceId]);
+        $this->executeList([$sourceCode]);
     }
 
     /**
      * @inheritdoc
      */
-    public function executeList(array $sourceIds)
+    public function executeList(array $sourceCodes)
     {
-        $stockIds = $this->getAssignedStockIds->execute($sourceIds);
+        $stockIds = $this->getAssignedStockIds->execute($sourceCodes);
         $this->stockIndexer->executeList($stockIds);
     }
 }
diff --git a/app/code/Magento/Inventory/Indexer/SourceItem/GetSkuListInStock.php b/app/code/Magento/Inventory/Indexer/SourceItem/GetSkuListInStock.php
index caca132f65b5..e1f11955cd0a 100644
--- a/app/code/Magento/Inventory/Indexer/SourceItem/GetSkuListInStock.php
+++ b/app/code/Magento/Inventory/Indexer/SourceItem/GetSkuListInStock.php
@@ -76,7 +76,11 @@ public function execute(array $sourceItemIds): array
                 ]
             )->joinInner(
                 ['stock_source_link' => $sourceStockLinkTable],
-                'source_item.' . SourceItemInterface::SOURCE_ID . ' = stock_source_link.' . StockSourceLink::SOURCE_ID,
+                sprintf(
+                    'source_item.%s = stock_source_link.%s',
+                    SourceItemInterface::SOURCE_CODE,
+                    StockSourceLink::SOURCE_CODE
+                ),
                 [StockSourceLink::STOCK_ID]
             )->where('source_item.source_item_id IN (?)', $sourceItemIds)
             ->group(['stock_source_link.' . StockSourceLink::STOCK_ID]);
diff --git a/app/code/Magento/Inventory/Indexer/SourceItem/SourceItemIndexer.php b/app/code/Magento/Inventory/Indexer/SourceItem/SourceItemIndexer.php
index 3a77edff1b5c..db90532bf8a8 100644
--- a/app/code/Magento/Inventory/Indexer/SourceItem/SourceItemIndexer.php
+++ b/app/code/Magento/Inventory/Indexer/SourceItem/SourceItemIndexer.php
@@ -13,7 +13,6 @@
 use Magento\Framework\MultiDimensionalIndex\IndexHandlerInterface;
 use Magento\Framework\MultiDimensionalIndex\IndexNameBuilder;
 use Magento\Framework\MultiDimensionalIndex\IndexStructureInterface;
-use Magento\Inventory\Indexer\IndexDataProvider;
 use Magento\Inventory\Indexer\Stock\StockIndexer;
 
 /**
@@ -96,9 +95,9 @@ public function executeFull()
     /**
      * @inheritdoc
      */
-    public function executeRow($sourceId)
+    public function executeRow($sourceItemId)
     {
-        $this->executeList([$sourceId]);
+        $this->executeList([$sourceItemId]);
     }
 
     /**
diff --git a/app/code/Magento/Inventory/Model/ResourceModel/Source.php b/app/code/Magento/Inventory/Model/ResourceModel/Source.php
index 178ee61dae21..5c0581cb702b 100644
--- a/app/code/Magento/Inventory/Model/ResourceModel/Source.php
+++ b/app/code/Magento/Inventory/Model/ResourceModel/Source.php
@@ -30,6 +30,13 @@ class Source extends AbstractDb
     const TABLE_NAME_SOURCE = 'inventory_source';
     /**#@-*/
 
+    /**
+     * Primary key auto increment flag
+     *
+     * @var bool
+     */
+    protected $_isPkAutoIncrement = false;
+
     /**
      * @var SourceCarrierLinkManagementInterface
      */
@@ -54,7 +61,7 @@ public function __construct(
      */
     protected function _construct()
     {
-        $this->_init(self::TABLE_NAME_SOURCE, SourceInterface::SOURCE_ID);
+        $this->_init(self::TABLE_NAME_SOURCE, SourceInterface::SOURCE_CODE);
     }
 
     /**
diff --git a/app/code/Magento/Inventory/Model/ResourceModel/SourceItem.php b/app/code/Magento/Inventory/Model/ResourceModel/SourceItem.php
old mode 100644
new mode 100755
diff --git a/app/code/Magento/Inventory/Model/ResourceModel/SourceItem/DeleteMultiple.php b/app/code/Magento/Inventory/Model/ResourceModel/SourceItem/DeleteMultiple.php
old mode 100644
new mode 100755
index 56c5ec475087..79c52d2e1590
--- a/app/code/Magento/Inventory/Model/ResourceModel/SourceItem/DeleteMultiple.php
+++ b/app/code/Magento/Inventory/Model/ResourceModel/SourceItem/DeleteMultiple.php
@@ -63,11 +63,11 @@ private function buildWhereSqlPart(array $sourceItems): string
                 SourceItemInterface::SKU . ' = ?',
                 $sourceItem->getSku()
             );
-            $sourceIdCondition = $connection->quoteInto(
-                SourceItemInterface::SOURCE_ID . ' = ?',
-                $sourceItem->getSourceId()
+            $sourceCodeCondition = $connection->quoteInto(
+                SourceItemInterface::SOURCE_CODE . ' = ?',
+                $sourceItem->getSourceCode()
             );
-            $condition[] = '(' . $skuCondition . ' AND ' . $sourceIdCondition . ')';
+            $condition[] = '(' . $skuCondition . ' AND ' . $sourceCodeCondition . ')';
         }
         return implode(' OR ', $condition);
     }
diff --git a/app/code/Magento/Inventory/Model/ResourceModel/SourceItem/SaveMultiple.php b/app/code/Magento/Inventory/Model/ResourceModel/SourceItem/SaveMultiple.php
old mode 100644
new mode 100755
index c9d1b4bcc347..22cec4f34d40
--- a/app/code/Magento/Inventory/Model/ResourceModel/SourceItem/SaveMultiple.php
+++ b/app/code/Magento/Inventory/Model/ResourceModel/SourceItem/SaveMultiple.php
@@ -46,7 +46,7 @@ public function execute(array $sourceItems)
         $tableName = $this->resourceConnection->getTableName(SourceItemResourceModel::TABLE_NAME_SOURCE_ITEM);
 
         $columnsSql = $this->buildColumnsSqlPart([
-            SourceItemInterface::SOURCE_ID,
+            SourceItemInterface::SOURCE_CODE,
             SourceItemInterface::SKU,
             SourceItemInterface::QUANTITY,
             SourceItemInterface::STATUS
@@ -100,7 +100,7 @@ private function getSqlBindData(array $sourceItems): array
         $bind = [];
         foreach ($sourceItems as $sourceItem) {
             $bind = array_merge($bind, [
-                $sourceItem->getSourceId(),
+                $sourceItem->getSourceCode(),
                 $sourceItem->getSku(),
                 $sourceItem->getQuantity(),
                 $sourceItem->getStatus(),
diff --git a/app/code/Magento/Inventory/Model/ResourceModel/StockSourceLink/SaveMultiple.php b/app/code/Magento/Inventory/Model/ResourceModel/StockSourceLink/SaveMultiple.php
index 2ab3dfe4be5e..be9f6effe76c 100644
--- a/app/code/Magento/Inventory/Model/ResourceModel/StockSourceLink/SaveMultiple.php
+++ b/app/code/Magento/Inventory/Model/ResourceModel/StockSourceLink/SaveMultiple.php
@@ -32,13 +32,13 @@ public function __construct(
     }
 
     /**
-     * @param array $sourceIds
+     * @param array $sourceCodes
      * @param int $stockId
      * @return void
      */
-    public function execute(array $sourceIds, int $stockId)
+    public function execute(array $sourceCodes, int $stockId)
     {
-        if (!count($sourceIds)) {
+        if (!count($sourceCodes)) {
             return;
         }
         $connection = $this->resourceConnection->getConnection();
@@ -47,13 +47,13 @@ public function execute(array $sourceIds, int $stockId)
         );
 
         $columns = [
-            StockSourceLink::SOURCE_ID,
+            StockSourceLink::SOURCE_CODE,
             StockSourceLink::STOCK_ID,
         ];
 
         $data = [];
-        foreach ($sourceIds as $sourceId) {
-            $data[] = [$sourceId, $stockId];
+        foreach ($sourceCodes as $sourceCode) {
+            $data[] = [$sourceCode, $stockId];
         }
         if ($data) {
             $connection->insertArray($tableName, $columns, $data);
diff --git a/app/code/Magento/Inventory/Model/Source.php b/app/code/Magento/Inventory/Model/Source.php
index d119ecae728f..6c66fff06d66 100644
--- a/app/code/Magento/Inventory/Model/Source.php
+++ b/app/code/Magento/Inventory/Model/Source.php
@@ -30,33 +30,17 @@ protected function _construct()
     /**
      * @inheritdoc
      */
-    public function getSourceId()
+    public function getSourceCode()
     {
-        return $this->getData(self::SOURCE_ID);
+        return $this->getData(self::SOURCE_CODE);
     }
 
     /**
      * @inheritdoc
      */
-    public function setSourceId($sourceId)
+    public function setSourceCode($sourceCode)
     {
-        $this->setData(self::SOURCE_ID, $sourceId);
-    }
-
-    /**
-     * @inheritdoc
-     */
-    public function getCode()
-    {
-        return $this->getData(self::CODE);
-    }
-
-    /**
-     * @inheritdoc
-     */
-    public function setCode($code)
-    {
-        return $this->setData(self::CODE, $code);
+        $this->setData(self::SOURCE_CODE, $sourceCode);
     }
 
     /**
diff --git a/app/code/Magento/Inventory/Model/Source/Command/Get.php b/app/code/Magento/Inventory/Model/Source/Command/Get.php
index 566c63c9c7d5..1b92625be539 100644
--- a/app/code/Magento/Inventory/Model/Source/Command/Get.php
+++ b/app/code/Magento/Inventory/Model/Source/Command/Get.php
@@ -42,14 +42,14 @@ public function __construct(
     /**
      * @inheritdoc
      */
-    public function execute(int $sourceId): SourceInterface
+    public function execute(string $sourceCode): SourceInterface
     {
         /** @var SourceInterface $source */
         $source = $this->sourceFactory->create();
-        $this->sourceResource->load($source, $sourceId, SourceInterface::SOURCE_ID);
+        $this->sourceResource->load($source, $sourceCode, SourceInterface::SOURCE_CODE);
 
-        if (null === $source->getSourceId()) {
-            throw new NoSuchEntityException(__('Source with id "%value" does not exist.', ['value' => $sourceId]));
+        if (null === $source->getSourceCode()) {
+            throw new NoSuchEntityException(__('Source with code "%value" does not exist.', ['value' => $sourceCode]));
         }
         return $source;
     }
diff --git a/app/code/Magento/Inventory/Model/Source/Command/GetInterface.php b/app/code/Magento/Inventory/Model/Source/Command/GetInterface.php
index 07e2c1bd3fca..390285fde244 100644
--- a/app/code/Magento/Inventory/Model/Source/Command/GetInterface.php
+++ b/app/code/Magento/Inventory/Model/Source/Command/GetInterface.php
@@ -11,7 +11,7 @@
 use Magento\InventoryApi\Api\Data\SourceInterface;
 
 /**
- * Get Source by sourceId command (Service Provider Interface - SPI)
+ * Get Source by code command (Service Provider Interface - SPI)
  *
  * Separate command interface to which Repository proxies initial Get call, could be considered as SPI - Interfaces
  * that you should extend and implement to customize current behaviour, but NOT expected to be used (called) in the code
@@ -23,11 +23,11 @@
 interface GetInterface
 {
     /**
-     * Get Source data by given sourceId
+     * Get Source data by given code
      *
-     * @param int $sourceId
+     * @param string $sourceCode
      * @return SourceInterface
      * @throws NoSuchEntityException
      */
-    public function execute(int $sourceId): SourceInterface;
+    public function execute(string $sourceCode): SourceInterface;
 }
diff --git a/app/code/Magento/Inventory/Model/Source/Command/Save.php b/app/code/Magento/Inventory/Model/Source/Command/Save.php
index f053df7b41a8..3718e8e1443f 100644
--- a/app/code/Magento/Inventory/Model/Source/Command/Save.php
+++ b/app/code/Magento/Inventory/Model/Source/Command/Save.php
@@ -52,7 +52,7 @@ public function __construct(
     /**
      * @inheritdoc
      */
-    public function execute(SourceInterface $source): int
+    public function execute(SourceInterface $source)
     {
         $validationResult = $this->sourceValidator->validate($source);
 
@@ -62,7 +62,7 @@ public function execute(SourceInterface $source): int
 
         try {
             $this->sourceResource->save($source);
-            return (int)$source->getSourceId();
+            $source->getSourceCode();
         } catch (\Exception $e) {
             $this->logger->error($e->getMessage());
             throw new CouldNotSaveException(__('Could not save Source'), $e);
diff --git a/app/code/Magento/Inventory/Model/Source/Command/SaveInterface.php b/app/code/Magento/Inventory/Model/Source/Command/SaveInterface.php
index e68908f35230..24e5805b069b 100644
--- a/app/code/Magento/Inventory/Model/Source/Command/SaveInterface.php
+++ b/app/code/Magento/Inventory/Model/Source/Command/SaveInterface.php
@@ -27,9 +27,9 @@ interface SaveInterface
      * Save Source data
      *
      * @param SourceInterface $source
-     * @return int
+     * @return void
      * @throws ValidationException
      * @throws CouldNotSaveException
      */
-    public function execute(SourceInterface $source): int;
+    public function execute(SourceInterface $source);
 }
diff --git a/app/code/Magento/Inventory/Model/Source/Validator/CodeValidator.php b/app/code/Magento/Inventory/Model/Source/Validator/CodeValidator.php
index dc7b2d1e3b5c..1151e1565023 100644
--- a/app/code/Magento/Inventory/Model/Source/Validator/CodeValidator.php
+++ b/app/code/Magento/Inventory/Model/Source/Validator/CodeValidator.php
@@ -34,16 +34,15 @@ public function __construct(ValidationResultFactory $validationResultFactory)
      */
     public function validate(SourceInterface $source): ValidationResult
     {
-        $value = (string)$source->getCode();
+        $value = (string)$source->getSourceCode();
 
         if ('' === trim($value)) {
-            $errors[] = __('"%field" can not be empty.', ['field' => SourceInterface::CODE]);
+            $errors[] = __('"%field" can not be empty.', ['field' => SourceInterface::SOURCE_CODE]);
         } elseif (preg_match('/\s/', $value)) {
-            $errors[] = __('"%field" can not contain whitespaces.', ['field' => SourceInterface::CODE]);
+            $errors[] = __('"%field" can not contain whitespaces.', ['field' => SourceInterface::SOURCE_CODE]);
         } else {
             $errors = [];
         }
-
         return $this->validationResultFactory->create(['errors' => $errors]);
     }
 }
diff --git a/app/code/Magento/Inventory/Model/Source/Validator/CountryValidator.php b/app/code/Magento/Inventory/Model/Source/Validator/CountryValidator.php
index 69754db85f5f..4483119e0cab 100644
--- a/app/code/Magento/Inventory/Model/Source/Validator/CountryValidator.php
+++ b/app/code/Magento/Inventory/Model/Source/Validator/CountryValidator.php
@@ -34,7 +34,7 @@ public function __construct(ValidationResultFactory $validationResultFactory)
      */
     public function validate(SourceInterface $source): ValidationResult
     {
-        $value = $source->getCountryId();
+        $value = (string)$source->getCountryId();
 
         if ('' === trim($value)) {
             $errors[] = __('"%field" can not be empty.', ['field' => SourceInterface::COUNTRY_ID]);
diff --git a/app/code/Magento/Inventory/Model/SourceCarrierLinkManagement.php b/app/code/Magento/Inventory/Model/SourceCarrierLinkManagement.php
index ce500a41c0a4..82179cd6368f 100644
--- a/app/code/Magento/Inventory/Model/SourceCarrierLinkManagement.php
+++ b/app/code/Magento/Inventory/Model/SourceCarrierLinkManagement.php
@@ -90,7 +90,7 @@ private function deleteCurrentCarrierLinks(SourceInterface $source)
         $connection = $this->resourceConnection->getConnection();
         $connection->delete(
             $this->resourceConnection->getTableName(SourceCarrierLink::TABLE_NAME_SOURCE_CARRIER_LINK),
-            $connection->quoteInto('source_id = ?', $source->getSourceId())
+            $connection->quoteInto('source_code = ?', $source->getSourceCode())
         );
     }
 
@@ -103,7 +103,7 @@ private function saveNewCarrierLinks(SourceInterface $source)
         $carrierLinkData = [];
         foreach ($source->getCarrierLinks() as $carrierLink) {
             $carrierLinkData[] = [
-                'source_id' => $source->getSourceId(),
+                'source_code' => $source->getSourceCode(),
                 SourceCarrierLinkInterface::CARRIER_CODE => $carrierLink->getCarrierCode(),
                 SourceCarrierLinkInterface::POSITION => $carrierLink->getPosition(),
             ];
@@ -121,7 +121,7 @@ private function saveNewCarrierLinks(SourceInterface $source)
     public function loadCarrierLinksBySource(SourceInterface $source)
     {
         $searchCriteria = $this->searchCriteriaBuilder
-            ->addFilter(SourceInterface::SOURCE_ID, $source->getSourceId())
+            ->addFilter(SourceCarrierLinkInterface::SOURCE_CODE, $source->getSourceCode())
             ->create();
 
         /** @var Collection $collection */
diff --git a/app/code/Magento/Inventory/Model/SourceItem.php b/app/code/Magento/Inventory/Model/SourceItem.php
old mode 100644
new mode 100755
index 3cc0a7911bc1..9dd5b5c36212
--- a/app/code/Magento/Inventory/Model/SourceItem.php
+++ b/app/code/Magento/Inventory/Model/SourceItem.php
@@ -46,17 +46,17 @@ public function setSku($sku)
     /**
      * @inheritdoc
      */
-    public function getSourceId()
+    public function getSourceCode()
     {
-        return $this->getData(self::SOURCE_ID);
+        return $this->getData(self::SOURCE_CODE);
     }
 
     /**
      * @inheritdoc
      */
-    public function setSourceId($sourceId)
+    public function setSourceCode($sourceCode)
     {
-        $this->setData(self::SOURCE_ID, $sourceId);
+        $this->setData(self::SOURCE_CODE, $sourceCode);
     }
 
     /**
diff --git a/app/code/Magento/Inventory/Model/SourceItem/Validator/SourceIdValidator.php b/app/code/Magento/Inventory/Model/SourceItem/Validator/SourceCodeValidator.php
similarity index 64%
rename from app/code/Magento/Inventory/Model/SourceItem/Validator/SourceIdValidator.php
rename to app/code/Magento/Inventory/Model/SourceItem/Validator/SourceCodeValidator.php
index 2e9175c9bdf9..777cd8d1f62d 100644
--- a/app/code/Magento/Inventory/Model/SourceItem/Validator/SourceIdValidator.php
+++ b/app/code/Magento/Inventory/Model/SourceItem/Validator/SourceCodeValidator.php
@@ -12,9 +12,9 @@
 use Magento\InventoryApi\Api\Data\SourceItemInterface;
 
 /**
- * Check that source id is valid
+ * Check that source code is valid
  */
-class SourceIdValidator implements SourceItemValidatorInterface
+class SourceCodeValidator implements SourceItemValidatorInterface
 {
     /**
      * @var ValidationResultFactory
@@ -34,14 +34,15 @@ public function __construct(ValidationResultFactory $validationResultFactory)
      */
     public function validate(SourceItemInterface $source): ValidationResult
     {
-        $errors = [];
-        if (!is_numeric($source->getSourceId())) {
-            $errors[] = __(
-                '"%field" should be numeric.',
-                ['field' => SourceItemInterface::SOURCE_ID]
-            );
-        }
+        $value = (string)$source->getSourceCode();
 
+        if ('' === trim($value)) {
+            $errors[] = __('"%field" can not be empty.', ['field' => SourceItemInterface::SOURCE_CODE]);
+        } elseif (preg_match('/\s/', $value)) {
+            $errors[] = __('"%field" can not contain whitespaces.', ['field' => SourceItemInterface::SOURCE_CODE]);
+        } else {
+            $errors = [];
+        }
         return $this->validationResultFactory->create(['errors' => $errors]);
     }
 }
diff --git a/app/code/Magento/Inventory/Model/SourceRepository.php b/app/code/Magento/Inventory/Model/SourceRepository.php
index ccc5c84043cb..8d2c10e4921b 100644
--- a/app/code/Magento/Inventory/Model/SourceRepository.php
+++ b/app/code/Magento/Inventory/Model/SourceRepository.php
@@ -53,17 +53,17 @@ public function __construct(
     /**
      * @inheritdoc
      */
-    public function save(SourceInterface $source): int
+    public function save(SourceInterface $source)
     {
-        return $this->commandSave->execute($source);
+        $this->commandSave->execute($source);
     }
 
     /**
      * @inheritdoc
      */
-    public function get(int $sourceId): SourceInterface
+    public function get(string $sourceCode): SourceInterface
     {
-        return $this->commandGet->execute($sourceId);
+        return $this->commandGet->execute($sourceCode);
     }
 
     /**
diff --git a/app/code/Magento/Inventory/Model/StockSourceLink.php b/app/code/Magento/Inventory/Model/StockSourceLink.php
index 3c409e2001d8..b3fd5caa963b 100644
--- a/app/code/Magento/Inventory/Model/StockSourceLink.php
+++ b/app/code/Magento/Inventory/Model/StockSourceLink.php
@@ -20,7 +20,7 @@ class StockSourceLink extends AbstractModel
     /**#@+
      * Constants for keys of data array. Identical to the name of the getter in snake case
      */
-    const SOURCE_ID = 'source_id';
+    const SOURCE_CODE = 'source_code';
     const STOCK_ID = 'stock_id';
     /**#@-*/
 
@@ -35,17 +35,17 @@ protected function _construct()
     /**
      * @inheritdoc
      */
-    public function getSourceId()
+    public function getSourceCode()
     {
-        return $this->getData(self::SOURCE_ID);
+        return $this->getData(self::SOURCE_CODE);
     }
 
     /**
      * @inheritdoc
      */
-    public function setSourceId($sourceId)
+    public function setSourceCode($sourceCode)
     {
-        $this->setData(self::SOURCE_ID, $sourceId);
+        $this->setData(self::SOURCE_CODE, $sourceCode);
     }
 
     /**
diff --git a/app/code/Magento/Inventory/Model/StockSourceLink/Command/AssignSourcesToStock.php b/app/code/Magento/Inventory/Model/StockSourceLink/Command/AssignSourcesToStock.php
index 0357e72342a3..a1ad33258eec 100644
--- a/app/code/Magento/Inventory/Model/StockSourceLink/Command/AssignSourcesToStock.php
+++ b/app/code/Magento/Inventory/Model/StockSourceLink/Command/AssignSourcesToStock.php
@@ -43,13 +43,13 @@ public function __construct(
     /**
      * @inheritdoc
      */
-    public function execute(array $sourceIds, int $stockId)
+    public function execute(array $sourceCodes, int $stockId)
     {
-        if (empty($sourceIds)) {
+        if (empty($sourceCodes)) {
             throw new InputException(__('Input data is invalid'));
         }
         try {
-            $this->saveMultiple->execute($sourceIds, $stockId);
+            $this->saveMultiple->execute($sourceCodes, $stockId);
         } catch (\Exception $e) {
             $this->logger->error($e->getMessage());
             throw new CouldNotSaveException(__('Could not assign Sources to Stock'), $e);
diff --git a/app/code/Magento/Inventory/Model/StockSourceLink/Command/GetAssignedSourcesForStock.php b/app/code/Magento/Inventory/Model/StockSourceLink/Command/GetAssignedSourcesForStock.php
index b189c6999ec7..e3787e889d62 100644
--- a/app/code/Magento/Inventory/Model/StockSourceLink/Command/GetAssignedSourcesForStock.php
+++ b/app/code/Magento/Inventory/Model/StockSourceLink/Command/GetAssignedSourcesForStock.php
@@ -67,10 +67,10 @@ public function __construct(
     public function execute(int $stockId): array
     {
         try {
-            $sourceIds = $this->getAssignedSourceIds($stockId);
+            $sourceCodes = $this->getAssignedSourceCodes($stockId);
 
             $searchCriteria = $this->searchCriteriaBuilder
-                ->addFilter(SourceInterface::SOURCE_ID, $sourceIds, 'in')
+                ->addFilter(SourceInterface::SOURCE_CODE, $sourceCodes, 'in')
                 ->create();
             $searchResult = $this->sourceRepository->getList($searchCriteria);
             return $searchResult->getItems();
@@ -81,19 +81,19 @@ public function execute(int $stockId): array
     }
 
     /**
-     * Get all linked SourceIds by given stockId
+     * Get all linked SourceCodes by given stockId
      *
      * @param int $stockId
      * @return array
      */
-    private function getAssignedSourceIds(int $stockId): array
+    private function getAssignedSourceCodes(int $stockId): array
     {
         $connection = $this->resourceConnection->getConnection();
         $select = $connection
             ->select()
             ->from(
                 $this->resourceConnection->getTableName(StockSourceLinkResourceModel::TABLE_NAME_STOCK_SOURCE_LINK),
-                [StockSourceLink::SOURCE_ID]
+                [StockSourceLink::SOURCE_CODE]
             )
             ->where(StockSourceLink::STOCK_ID . ' = ?', $stockId);
         return $connection->fetchCol($select);
diff --git a/app/code/Magento/Inventory/Model/StockSourceLink/Command/UnassignSourceFromStock.php b/app/code/Magento/Inventory/Model/StockSourceLink/Command/UnassignSourceFromStock.php
index 6b13bc5dd048..19b030445825 100644
--- a/app/code/Magento/Inventory/Model/StockSourceLink/Command/UnassignSourceFromStock.php
+++ b/app/code/Magento/Inventory/Model/StockSourceLink/Command/UnassignSourceFromStock.php
@@ -72,11 +72,11 @@ public function __construct(
     /**
      * @inheritdoc
      */
-    public function execute(int $sourceId, int $stockId)
+    public function execute(string $sourceCode, int $stockId)
     {
         $searchCriteria = $this->searchCriteriaBuilder
             ->addFilter(StockSourceLink::STOCK_ID, (int)$stockId)
-            ->addFilter(StockSourceLink::SOURCE_ID, $sourceId)
+            ->addFilter(StockSourceLink::SOURCE_CODE, $sourceCode)
             ->create();
 
         /** @var Collection $collection */
diff --git a/app/code/Magento/Inventory/Setup/Operation/CreateSourceCarrierLinkTable.php b/app/code/Magento/Inventory/Setup/Operation/CreateSourceCarrierLinkTable.php
index 703b18040a74..6aa5201fc5fb 100644
--- a/app/code/Magento/Inventory/Setup/Operation/CreateSourceCarrierLinkTable.php
+++ b/app/code/Magento/Inventory/Setup/Operation/CreateSourceCarrierLinkTable.php
@@ -53,14 +53,13 @@ private function createSourceCarrierLinkTable(SchemaSetupInterface $setup): Tabl
             ],
             'Source Carrier Link ID'
         )->addColumn(
-            SourceInterface::SOURCE_ID,
-            Table::TYPE_INTEGER,
-            null,
+            SourceCarrierLinkInterface::SOURCE_CODE,
+            Table::TYPE_TEXT,
+            255,
             [
                 Table::OPTION_NULLABLE => false,
-                Table::OPTION_UNSIGNED => true,
             ],
-            'Source ID'
+            'Source Code'
         )->addColumn(
             SourceCarrierLinkInterface::CARRIER_CODE,
             Table::TYPE_TEXT,
@@ -81,13 +80,13 @@ private function createSourceCarrierLinkTable(SchemaSetupInterface $setup): Tabl
         )->addForeignKey(
             $setup->getFkName(
                 $sourceCarrierLinkTable,
-                SourceInterface::SOURCE_ID,
+                SourceCarrierLinkInterface::SOURCE_CODE,
                 $sourceTable,
-                SourceInterface::SOURCE_ID
+                SourceInterface::SOURCE_CODE
             ),
-            SourceInterface::SOURCE_ID,
+            SourceCarrierLinkInterface::SOURCE_CODE,
             $sourceTable,
-            SourceInterface::SOURCE_ID,
+            SourceInterface::SOURCE_CODE,
             AdapterInterface::FK_ACTION_CASCADE
         );
     }
diff --git a/app/code/Magento/Inventory/Setup/Operation/CreateSourceItemTable.php b/app/code/Magento/Inventory/Setup/Operation/CreateSourceItemTable.php
old mode 100644
new mode 100755
index a6c8b5cc225f..f0e0405cb3a1
--- a/app/code/Magento/Inventory/Setup/Operation/CreateSourceItemTable.php
+++ b/app/code/Magento/Inventory/Setup/Operation/CreateSourceItemTable.php
@@ -53,14 +53,13 @@ private function createSourceItemTable(SchemaSetupInterface $setup): Table
             ],
             'Source Item ID'
         )->addColumn(
-            SourceItemInterface::SOURCE_ID,
-            Table::TYPE_INTEGER,
-            null,
+            SourceItemInterface::SOURCE_CODE,
+            Table::TYPE_TEXT,
+            255,
             [
-                Table::OPTION_UNSIGNED => true,
                 Table::OPTION_NULLABLE => false,
             ],
-            'Source ID'
+            'Source Code'
         )->addColumn(
             SourceItemInterface::SKU,
             Table::TYPE_TEXT,
@@ -94,25 +93,25 @@ private function createSourceItemTable(SchemaSetupInterface $setup): Table
         )->addForeignKey(
             $setup->getFkName(
                 $sourceItemTable,
-                SourceItemInterface::SOURCE_ID,
+                SourceItemInterface::SOURCE_CODE,
                 $sourceTable,
-                SourceInterface::SOURCE_ID
+                SourceInterface::SOURCE_CODE
             ),
-            SourceItemInterface::SOURCE_ID,
+            SourceItemInterface::SOURCE_CODE,
             $sourceTable,
-            SourceInterface::SOURCE_ID,
+            SourceInterface::SOURCE_CODE,
             AdapterInterface::FK_ACTION_CASCADE
         )->addIndex(
             $setup->getIdxName(
                 $sourceItemTable,
                 [
-                    SourceItemInterface::SOURCE_ID,
+                    SourceItemInterface::SOURCE_CODE,
                     SourceItemInterface::SKU,
                 ],
                 AdapterInterface::INDEX_TYPE_UNIQUE
             ),
             [
-                SourceItemInterface::SOURCE_ID,
+                SourceItemInterface::SOURCE_CODE,
                 SourceItemInterface::SKU,
             ],
             ['type' => AdapterInterface::INDEX_TYPE_UNIQUE]
diff --git a/app/code/Magento/Inventory/Setup/Operation/CreateSourceTable.php b/app/code/Magento/Inventory/Setup/Operation/CreateSourceTable.php
index 9c9738398c83..219e20c2c86b 100644
--- a/app/code/Magento/Inventory/Setup/Operation/CreateSourceTable.php
+++ b/app/code/Magento/Inventory/Setup/Operation/CreateSourceTable.php
@@ -38,7 +38,6 @@ public function execute(SchemaSetupInterface $setup)
         $sourceTable = $this->addAddressFields($sourceTable);
         $sourceTable = $this->addContactInfoFields($sourceTable);
         $sourceTable = $this->addSourceCarrierFields($sourceTable);
-        $sourceTable = $this->addIndex($sourceTable, $setup);
 
         $setup->getConnection()->createTable($sourceTable);
     }
@@ -50,22 +49,12 @@ public function execute(SchemaSetupInterface $setup)
     private function addBaseFields(Table $sourceTable): Table
     {
         return $sourceTable->addColumn(
-            SourceInterface::SOURCE_ID,
-            Table::TYPE_INTEGER,
-            null,
-            [
-                Table::OPTION_IDENTITY => true,
-                Table::OPTION_UNSIGNED => true,
-                Table::OPTION_NULLABLE => false,
-                Table::OPTION_PRIMARY => true,
-            ],
-            'Source ID'
-        )->addColumn(
-            SourceInterface::CODE,
+            SourceInterface::SOURCE_CODE,
             Table::TYPE_TEXT,
             255,
             [
                 Table::OPTION_NULLABLE => false,
+                Table::OPTION_PRIMARY => true,
             ],
             'Source Code'
         )->addColumn(
@@ -132,7 +121,7 @@ private function addBaseFields(Table $sourceTable): Table
      * @param Table $sourceTable
      * @return Table
      */
-    private function addAddressFields(Table $sourceTable)
+    private function addAddressFields(Table $sourceTable): Table
     {
         $sourceTable->addColumn(
             SourceInterface::COUNTRY_ID,
@@ -191,7 +180,7 @@ private function addAddressFields(Table $sourceTable)
      * @param Table $sourceTable
      * @return Table
      */
-    private function addContactInfoFields(Table $sourceTable)
+    private function addContactInfoFields(Table $sourceTable): Table
     {
         $sourceTable->addColumn(
             SourceInterface::CONTACT_NAME,
@@ -233,7 +222,7 @@ private function addContactInfoFields(Table $sourceTable)
      * @param Table $sourceTable
      * @return Table
      */
-    private function addSourceCarrierFields(Table $sourceTable)
+    private function addSourceCarrierFields(Table $sourceTable): Table
     {
         $sourceTable->addColumn(
             'use_default_carrier_config',
@@ -248,21 +237,4 @@ private function addSourceCarrierFields(Table $sourceTable)
         );
         return $sourceTable;
     }
-
-    private function addIndex(Table $sourceTable, SchemaSetupInterface $setup)
-    {
-        return $sourceTable->addIndex(
-            $setup->getIdxName(
-                $setup->getTable(SourceResourceModel::TABLE_NAME_SOURCE),
-                [
-                    SourceInterface::CODE
-                ],
-                AdapterInterface::INDEX_TYPE_UNIQUE
-            ),
-            [
-                SourceInterface::CODE
-            ],
-            ['type' => AdapterInterface::INDEX_TYPE_UNIQUE]
-        );
-    }
 }
diff --git a/app/code/Magento/Inventory/Setup/Operation/CreateStockSourceLinkTable.php b/app/code/Magento/Inventory/Setup/Operation/CreateStockSourceLinkTable.php
index f90c204bd01a..71c4524aa8f7 100644
--- a/app/code/Magento/Inventory/Setup/Operation/CreateStockSourceLinkTable.php
+++ b/app/code/Magento/Inventory/Setup/Operation/CreateStockSourceLinkTable.php
@@ -65,14 +65,13 @@ private function createStockSourceLinkTable(SchemaSetupInterface $setup): Table
             ],
             'Stock ID'
         )->addColumn(
-            StockSourceLink::SOURCE_ID,
-            Table::TYPE_INTEGER,
-            null,
+            StockSourceLink::SOURCE_CODE,
+            Table::TYPE_TEXT,
+            255,
             [
                 Table::OPTION_NULLABLE => false,
-                Table::OPTION_UNSIGNED => true,
             ],
-            'Source ID'
+            'Source Code'
         )->addForeignKey(
             $setup->getFkName(
                 $stockSourceLinkTable,
@@ -87,26 +86,26 @@ private function createStockSourceLinkTable(SchemaSetupInterface $setup): Table
         )->addForeignKey(
             $setup->getFkName(
                 $stockSourceLinkTable,
-                StockSourceLink::SOURCE_ID,
+                StockSourceLink::SOURCE_CODE,
                 $sourceTable,
-                SourceInterface::SOURCE_ID
+                SourceInterface::SOURCE_CODE
             ),
-            StockSourceLink::SOURCE_ID,
+            StockSourceLink::SOURCE_CODE,
             $sourceTable,
-            SourceInterface::SOURCE_ID,
+            SourceInterface::SOURCE_CODE,
             AdapterInterface::FK_ACTION_CASCADE
         )->addIndex(
             $setup->getIdxName(
                 $stockSourceLinkTable,
                 [
                     StockSourceLink::STOCK_ID,
-                    StockSourceLink::SOURCE_ID,
+                    StockSourceLink::SOURCE_CODE,
                 ],
                 AdapterInterface::INDEX_TYPE_UNIQUE
             ),
             [
                 StockSourceLink::STOCK_ID,
-                StockSourceLink::SOURCE_ID,
+                StockSourceLink::SOURCE_CODE,
             ],
             ['type' => AdapterInterface::INDEX_TYPE_UNIQUE]
         );
diff --git a/app/code/Magento/Inventory/Test/Integration/Indexer/GetSourceItemId.php b/app/code/Magento/Inventory/Test/Integration/Indexer/GetSourceItemId.php
index d98d968250b0..c40b13b31f73 100644
--- a/app/code/Magento/Inventory/Test/Integration/Indexer/GetSourceItemId.php
+++ b/app/code/Magento/Inventory/Test/Integration/Indexer/GetSourceItemId.php
@@ -28,10 +28,10 @@ public function __construct(ResourceConnection $resourceConnection)
 
     /**
      * @param string $sku
-     * @param int $sourceId
+     * @param string $sourceCode
      * @return int
      */
-    public function execute(string $sku, int $sourceId): int
+    public function execute(string $sku, string $sourceCode): int
     {
         $connection = $this->resourceConnection->getConnection();
         $select = $connection->select()
@@ -40,7 +40,7 @@ public function execute(string $sku, int $sourceId): int
                 [SourceItemResourceModel::ID_FIELD_NAME]
             )
             ->where(SourceItemInterface::SKU . ' = ?', $sku)
-            ->where(SourceItemInterface::SOURCE_ID . ' = ?', $sourceId);
+            ->where(SourceItemInterface::SOURCE_CODE . ' = ?', $sourceCode);
 
         return (int)$connection->fetchOne($select);
     }
diff --git a/app/code/Magento/Inventory/Test/Integration/Indexer/SourceIndexerTest.php b/app/code/Magento/Inventory/Test/Integration/Indexer/SourceIndexerTest.php
index d3b93319ec2f..26176b0a7548 100644
--- a/app/code/Magento/Inventory/Test/Integration/Indexer/SourceIndexerTest.php
+++ b/app/code/Magento/Inventory/Test/Integration/Indexer/SourceIndexerTest.php
@@ -56,7 +56,7 @@ protected function tearDown()
      */
     public function testReindexRow()
     {
-        $this->indexer->reindexRow(10);
+        $this->indexer->reindexRow('eu-1');
 
         self::assertEquals(8.5, $this->getProductQuantityInStock->execute('SKU-1', 10));
         self::assertEquals(8.5, $this->getProductQuantityInStock->execute('SKU-1', 30));
@@ -71,7 +71,7 @@ public function testReindexRow()
      */
     public function testReindexList()
     {
-        $this->indexer->reindexList([10, 50]);
+        $this->indexer->reindexList(['eu-1', 'us-1']);
 
         self::assertEquals(8.5, $this->getProductQuantityInStock->execute('SKU-1', 10));
         self::assertEquals(8.5, $this->getProductQuantityInStock->execute('SKU-1', 30));
diff --git a/app/code/Magento/Inventory/Test/Integration/Indexer/SourceItemIndexerTest.php b/app/code/Magento/Inventory/Test/Integration/Indexer/SourceItemIndexerTest.php
index e6f934cad4db..d744fe19ddc6 100644
--- a/app/code/Magento/Inventory/Test/Integration/Indexer/SourceItemIndexerTest.php
+++ b/app/code/Magento/Inventory/Test/Integration/Indexer/SourceItemIndexerTest.php
@@ -63,7 +63,7 @@ protected function tearDown()
      */
     public function testReindexRow()
     {
-        $this->indexer->reindexRow($this->getSourceItemId->execute('SKU-1', 10));
+        $this->indexer->reindexRow($this->getSourceItemId->execute('SKU-1', 'eu-1'));
 
         self::assertEquals(8.5, $this->getProductQuantityInStock->execute('SKU-1', 10));
         self::assertEquals(8.5, $this->getProductQuantityInStock->execute('SKU-1', 30));
@@ -79,8 +79,8 @@ public function testReindexRow()
     public function testReindexList()
     {
         $this->indexer->reindexList([
-            $this->getSourceItemId->execute('SKU-1', 10),
-            $this->getSourceItemId->execute('SKU-2', 50),
+            $this->getSourceItemId->execute('SKU-1', 'eu-1'),
+            $this->getSourceItemId->execute('SKU-2', 'us-1'),
         ]);
 
         self::assertEquals(8.5, $this->getProductQuantityInStock->execute('SKU-1', 10));
diff --git a/app/code/Magento/Inventory/Test/Unit/Model/Source/Validator/CodeValidatorTest.php b/app/code/Magento/Inventory/Test/Unit/Model/Source/Validator/CodeValidatorTest.php
index f035068929f1..0c4584203237 100644
--- a/app/code/Magento/Inventory/Test/Unit/Model/Source/Validator/CodeValidatorTest.php
+++ b/app/code/Magento/Inventory/Test/Unit/Model/Source/Validator/CodeValidatorTest.php
@@ -43,14 +43,14 @@ public function testValidateCodeNotEmpty()
         $emptyValidatorResult = $this->createMock(\Magento\Framework\Validation\ValidationResult::class);
         $this->validationResultFactory->expects($this->once())
             ->method('create')
-            ->with(['errors' => [__('"%field" can not be empty.', ['field' => SourceInterface::CODE])]])
+            ->with(['errors' => [__('"%field" can not be empty.', ['field' => SourceInterface::SOURCE_CODE])]])
             ->willReturn($emptyValidatorResult);
         $this->codeValidator = (new ObjectManager($this))->getObject(CodeValidator::class, [
             'validationResultFactory' => $this->validationResultFactory
         ]);
 
         $this->source->expects($this->once())
-            ->method('getCode')
+            ->method('getSourceCode')
             ->willReturn('  ');
         $this->codeValidator->validate($this->source);
     }
@@ -60,13 +60,15 @@ public function testValidateCodeNotWithWhiteSpaces()
         $emptyValidatorResult = $this->createMock(\Magento\Framework\Validation\ValidationResult::class);
         $this->validationResultFactory->expects($this->once())
             ->method('create')
-            ->with(['errors' => [__('"%field" can not contain whitespaces.', ['field' => SourceInterface::CODE])]])
+            ->with([
+                'errors' => [__('"%field" can not contain whitespaces.', ['field' => SourceInterface::SOURCE_CODE])]
+            ])
             ->willReturn($emptyValidatorResult);
         $this->codeValidator = (new ObjectManager($this))->getObject(CodeValidator::class, [
             'validationResultFactory' => $this->validationResultFactory
         ]);
         $this->source->expects($this->once())
-            ->method('getCode')
+            ->method('getSourceCode')
             ->willReturn(' source code ');
         $this->codeValidator->validate($this->source);
     }
@@ -81,7 +83,7 @@ public function testValidateCodeSuccessfully()
             'validationResultFactory' => $this->validationResultFactory
         ]);
         $this->source->expects($this->once())
-            ->method('getCode')
+            ->method('getSourceCode')
             ->willReturn(' source_code ');
 
         $result = $this->codeValidator->validate($this->source);
diff --git a/app/code/Magento/Inventory/Test/Unit/Model/SourceRepositoryTest.php b/app/code/Magento/Inventory/Test/Unit/Model/SourceRepositoryTest.php
index 1423f3584a97..1b0636873187 100644
--- a/app/code/Magento/Inventory/Test/Unit/Model/SourceRepositoryTest.php
+++ b/app/code/Magento/Inventory/Test/Unit/Model/SourceRepositoryTest.php
@@ -71,15 +71,15 @@ protected function setUp()
 
     public function testSave()
     {
-        $sourceId = 42;
+        $sourceCode = 'source-code';
 
         $this->commandSave
             ->expects($this->once())
             ->method('execute')
             ->with($this->source)
-            ->willReturn($sourceId);
+            ->willReturn($sourceCode);
 
-        self::assertEquals($sourceId, $this->sourceRepository->save($this->source));
+        $this->sourceRepository->save($this->source);
     }
 
     /**
@@ -99,15 +99,15 @@ public function testSaveWithCouldNotSaveException()
 
     public function testGet()
     {
-        $sourceId = 42;
+        $sourceCode = 'source-code';
 
         $this->commandGet
             ->expects($this->once())
             ->method('execute')
-            ->with($sourceId)
+            ->with($sourceCode)
             ->willReturn($this->source);
 
-        self::assertEquals($this->source, $this->sourceRepository->get($sourceId));
+        self::assertEquals($this->source, $this->sourceRepository->get($sourceCode));
     }
 
     /**
@@ -116,15 +116,15 @@ public function testGet()
      */
     public function testGetWithNoSuchEntityException()
     {
-        $sourceId = 42;
+        $sourceCode = 'source-code';
 
         $this->commandGet
             ->expects($this->once())
             ->method('execute')
-            ->with($sourceId)
+            ->with($sourceCode)
             ->willThrowException(new NoSuchEntityException(__('Some error')));
 
-        $this->sourceRepository->get($sourceId);
+        $this->sourceRepository->get($sourceCode);
     }
 
     public function testGetListWithoutSearchCriteria()
diff --git a/app/code/Magento/Inventory/Ui/DataProvider/SourceDataProvider.php b/app/code/Magento/Inventory/Ui/DataProvider/SourceDataProvider.php
index d9604018c039..48e7cb664e21 100644
--- a/app/code/Magento/Inventory/Ui/DataProvider/SourceDataProvider.php
+++ b/app/code/Magento/Inventory/Ui/DataProvider/SourceDataProvider.php
@@ -83,10 +83,10 @@ public function getData()
             // It is need for support of several fieldsets.
             // For details see \Magento\Ui\Component\Form::getDataSourceData
             if ($data['totalRecords'] > 0) {
-                $sourceId = (int)$data['items'][0][SourceInterface::SOURCE_ID];
+                $sourceCode = $data['items'][0][SourceInterface::SOURCE_CODE];
                 $sourceGeneralData = $data['items'][0];
-                $sourceGeneralData['carrier_codes'] =  $this->getAssignedCarrierCodes($sourceId);
-                $dataForSingle[$sourceId] = [
+                $sourceGeneralData['carrier_codes'] =  $this->getAssignedCarrierCodes($sourceCode);
+                $dataForSingle[$sourceCode] = [
                     'general' => $sourceGeneralData,
                 ];
                 $data = $dataForSingle;
@@ -109,18 +109,18 @@ public function getSearchResult()
             $result->getItems(),
             $result->getTotalCount(),
             $searchCriteria,
-            SourceInterface::SOURCE_ID
+            SourceInterface::SOURCE_CODE
         );
         return $searchResult;
     }
 
     /**
-     * @param int $sourceId
+     * @param string $sourceCode
      * @return array
      */
-    private function getAssignedCarrierCodes(int $sourceId): array
+    private function getAssignedCarrierCodes(string $sourceCode): array
     {
-        $source = $this->sourceRepository->get($sourceId);
+        $source = $this->sourceRepository->get($sourceCode);
         $carrierCodes = [];
 
         $carrierLinks = $source->getCarrierLinks();
diff --git a/app/code/Magento/Inventory/Ui/DataProvider/StockDataProvider.php b/app/code/Magento/Inventory/Ui/DataProvider/StockDataProvider.php
index 38b1cd0aa32a..85eb3d8daac9 100644
--- a/app/code/Magento/Inventory/Ui/DataProvider/StockDataProvider.php
+++ b/app/code/Magento/Inventory/Ui/DataProvider/StockDataProvider.php
@@ -137,7 +137,7 @@ private function getAssignedSourcesData(int $stockId): array
         $assignedSourcesData = [];
         foreach ($assignedSources as $assignedSource) {
             $assignedSourcesData[] = [
-                SourceInterface::SOURCE_ID => $assignedSource->getSourceId(),
+                SourceInterface::SOURCE_CODE => $assignedSource->getSourceCode(),
                 SourceInterface::NAME => $assignedSource->getName(),
             ];
         }
diff --git a/app/code/Magento/Inventory/etc/di.xml b/app/code/Magento/Inventory/etc/di.xml
index 6acb6ca0aa86..7707f30d0d8e 100644
--- a/app/code/Magento/Inventory/etc/di.xml
+++ b/app/code/Magento/Inventory/etc/di.xml
@@ -42,7 +42,7 @@
         <arguments>
             <argument name="validators" xsi:type="array">
                 <item name="sku" xsi:type="object">Magento\Inventory\Model\SourceItem\Validator\SkuValidator</item>
-                <item name="sourceId" xsi:type="object">Magento\Inventory\Model\SourceItem\Validator\SourceIdValidator</item>
+                <item name="source_code" xsi:type="object">Magento\Inventory\Model\SourceItem\Validator\SourceCodeValidator</item>
                 <item name="quantity" xsi:type="object">Magento\Inventory\Model\SourceItem\Validator\QuantityValidator</item>
                 <item name="status" xsi:type="object">Magento\Inventory\Model\SourceItem\Validator\StatusValidator</item>
             </argument>
diff --git a/app/code/Magento/Inventory/etc/mview.xml b/app/code/Magento/Inventory/etc/mview.xml
index 44a586422a35..ebb3b0aa45d4 100644
--- a/app/code/Magento/Inventory/etc/mview.xml
+++ b/app/code/Magento/Inventory/etc/mview.xml
@@ -13,7 +13,7 @@
     </view>
     <view id="inventory_source" class="Magento\Inventory\Indexer\Source\Mview\Action" group="indexer">
         <subscriptions>
-            <table name="inventory_source" entity_column="source_id" />
+            <table name="inventory_source" entity_column="source_code" />
         </subscriptions>
     </view>
     <view id="inventory_source_item" class="Magento\Inventory\Indexer\SourceItem\Mview\Action" group="indexer">
diff --git a/app/code/Magento/Inventory/view/adminhtml/ui_component/inventory_source_form.xml b/app/code/Magento/Inventory/view/adminhtml/ui_component/inventory_source_form.xml
index 78aed75bcf76..90fae339e52b 100644
--- a/app/code/Magento/Inventory/view/adminhtml/ui_component/inventory_source_form.xml
+++ b/app/code/Magento/Inventory/view/adminhtml/ui_component/inventory_source_form.xml
@@ -38,8 +38,8 @@
         </settings>
         <dataProvider class="Magento\Inventory\Ui\DataProvider\SourceDataProvider" name="inventory_source_form_data_source">
             <settings>
-                <requestFieldName>source_id</requestFieldName>
-                <primaryFieldName>source_id</primaryFieldName>
+                <requestFieldName>source_code</requestFieldName>
+                <primaryFieldName>source_code</primaryFieldName>
             </settings>
         </dataProvider>
     </dataSource>
@@ -50,7 +50,7 @@
             <opened>true</opened>
             <dataScope>general</dataScope>
         </settings>
-        <field name="code" formElement="input" sortOrder="20">
+        <field name="source_code" formElement="input" sortOrder="20">
             <settings>
                 <validation>
                     <rule name="required-entry" xsi:type="boolean">true</rule>
diff --git a/app/code/Magento/Inventory/view/adminhtml/ui_component/inventory_source_listing.xml b/app/code/Magento/Inventory/view/adminhtml/ui_component/inventory_source_listing.xml
index 7dbad88c838f..4b58b782d07e 100644
--- a/app/code/Magento/Inventory/view/adminhtml/ui_component/inventory_source_listing.xml
+++ b/app/code/Magento/Inventory/view/adminhtml/ui_component/inventory_source_listing.xml
@@ -27,15 +27,15 @@
     <dataSource name="inventory_source_listing_data_source" component="Magento_Ui/js/grid/provider">
         <settings>
             <storageConfig>
-                <param name="indexField" xsi:type="string">source_id</param>
+                <param name="indexField" xsi:type="string">source_code</param>
             </storageConfig>
             <updateUrl path="mui/index/render"/>
         </settings>
         <aclResource>Magento_InventoryApi::source</aclResource>
         <dataProvider class="Magento\Inventory\Ui\DataProvider\SourceDataProvider" name="inventory_source_listing_data_source">
             <settings>
-                <requestFieldName>id</requestFieldName>
-                <primaryFieldName>source_id</primaryFieldName>
+                <requestFieldName>source_code</requestFieldName>
+                <primaryFieldName>source_code</primaryFieldName>
             </settings>
         </dataProvider>
     </dataSource>
@@ -68,7 +68,7 @@
                     <item name="saveUrl" xsi:type="url" path="inventory/source/inlineEdit"/>
                     <item name="validateBeforeSave" xsi:type="boolean">false</item>
                 </param>
-                <param name="indexField" xsi:type="string">source_id</param>
+                <param name="indexField" xsi:type="string">source_code</param>
                 <param name="enabled" xsi:type="boolean">true</param>
                 <param name="selectProvider" xsi:type="string">inventory_source_listing.inventory_source_listing.inventory_source_listing_columns.ids</param>
             </editorConfig>
@@ -85,17 +85,10 @@
         </settings>
         <selectionsColumn name="ids" sortOrder="10">
             <settings>
-                <indexField>source_id</indexField>
+                <indexField>source_code</indexField>
             </settings>
         </selectionsColumn>
-        <column name="source_id" sortOrder="20">
-            <settings>
-                <filter>textRange</filter>
-                <label translate="true">ID</label>
-                <sorting>asc</sorting>
-            </settings>
-        </column>
-        <column name="code" sortOrder="25">
+        <column name="source_code" sortOrder="25">
             <settings>
                 <filter>text</filter>
                 <label translate="true">Code</label>
@@ -288,7 +281,7 @@
                 </item>
             </argument>
             <settings>
-                <indexField>source_id</indexField>
+                <indexField>source_code</indexField>
             </settings>
         </actionsColumn>
     </columns>
diff --git a/app/code/Magento/Inventory/view/adminhtml/ui_component/inventory_stock_form.xml b/app/code/Magento/Inventory/view/adminhtml/ui_component/inventory_stock_form.xml
index 50e3b47b127a..45cb7af02888 100644
--- a/app/code/Magento/Inventory/view/adminhtml/ui_component/inventory_stock_form.xml
+++ b/app/code/Magento/Inventory/view/adminhtml/ui_component/inventory_stock_form.xml
@@ -100,10 +100,10 @@
                 <item name="js_config" xsi:type="array">
                     <item name="dataProvider" xsi:type="string">data.sources.assign_sources_grid</item>
                     <item name="map" xsi:type="array">
-                        <item name="source_id" xsi:type="string">source_id</item>
+                        <item name="source_code" xsi:type="string">source_code</item>
                         <item name="name" xsi:type="string">name</item>
                     </item>
-                    <item name="identificationDRProperty" xsi:type="string">source_id</item>
+                    <item name="identificationDRProperty" xsi:type="string">source_code</item>
                 </item>
             </argument>
             <settings>
@@ -111,7 +111,7 @@
                 <defaultRecord>false</defaultRecord>
                 <addButton>false</addButton>
                 <recordTemplate>record</recordTemplate>
-                <identificationProperty>source_id</identificationProperty>
+                <identificationProperty>source_code</identificationProperty>
                 <links>
                     <link name="insertData">${ $.provider }:${ $.dataProvider }</link>
                 </links>
@@ -128,12 +128,12 @@
                         <item name="dataScope" xsi:type="string"/>
                     </item>
                 </argument>
-                <field name="source_id" formElement="input" sortOrder="10">
+                <field name="source_code" formElement="input" sortOrder="10">
                     <settings>
                         <elementTmpl>ui/dynamic-rows/cells/text</elementTmpl>
                         <dataType>text</dataType>
-                        <dataScope>source_id</dataScope>
-                        <label translate="true">ID</label>
+                        <dataScope>source_code</dataScope>
+                        <label translate="true">Code</label>
                     </settings>
                 </field>
                 <field name="name" formElement="input" sortOrder="20">
diff --git a/app/code/Magento/InventoryApi/Api/AssignSourcesToStockInterface.php b/app/code/Magento/InventoryApi/Api/AssignSourcesToStockInterface.php
index ad3f0bfb4c5f..0aac6952eeb7 100644
--- a/app/code/Magento/InventoryApi/Api/AssignSourcesToStockInterface.php
+++ b/app/code/Magento/InventoryApi/Api/AssignSourcesToStockInterface.php
@@ -21,11 +21,11 @@ interface AssignSourcesToStockInterface
      *
      * If one of the Sources or Stock with given id don't exist then exception will be throw
      *
-     * @param int[] $sourceIds
+     * @param string[] $sourceCodes
      * @param int $stockId
      * @return void
      * @throws \Magento\Framework\Exception\InputException
      * @throws \Magento\Framework\Exception\CouldNotSaveException
      */
-    public function execute(array $sourceIds, int $stockId);
+    public function execute(array $sourceCodes, int $stockId);
 }
diff --git a/app/code/Magento/InventoryApi/Api/Data/SourceCarrierLinkInterface.php b/app/code/Magento/InventoryApi/Api/Data/SourceCarrierLinkInterface.php
index 4b6acd8069dd..27c4b476ee41 100644
--- a/app/code/Magento/InventoryApi/Api/Data/SourceCarrierLinkInterface.php
+++ b/app/code/Magento/InventoryApi/Api/Data/SourceCarrierLinkInterface.php
@@ -23,6 +23,7 @@ interface SourceCarrierLinkInterface extends ExtensibleDataInterface
      */
     const CARRIER_CODE = 'carrier_code';
     const POSITION = 'position';
+    const SOURCE_CODE = 'source_code';
     /**#@-*/
 
     /**
diff --git a/app/code/Magento/InventoryApi/Api/Data/SourceInterface.php b/app/code/Magento/InventoryApi/Api/Data/SourceInterface.php
index 8a834b062c17..6a74a5186c13 100644
--- a/app/code/Magento/InventoryApi/Api/Data/SourceInterface.php
+++ b/app/code/Magento/InventoryApi/Api/Data/SourceInterface.php
@@ -21,8 +21,7 @@ interface SourceInterface extends ExtensibleDataInterface
     /**
      * Constants for keys of data array. Identical to the name of the getter in snake case
      */
-    const SOURCE_ID = 'source_id';
-    const CODE = 'code';
+    const SOURCE_CODE = 'source_code';
     const NAME = 'name';
     const CONTACT_NAME = 'contact_name';
     const EMAIL = 'email';
@@ -42,35 +41,20 @@ interface SourceInterface extends ExtensibleDataInterface
     const USE_DEFAULT_CARRIER_CONFIG = 'use_default_carrier_config';
     const CARRIER_LINKS = 'carrier_links';
 
-    /**
-     * Get source id
-     *
-     * @return int|null
-     */
-    public function getSourceId();
-
-    /**
-     * Set source id
-     *
-     * @param int|null $sourceId
-     * @return void
-     */
-    public function setSourceId($sourceId);
-
     /**
      * Get source code
      *
      * @return string|null
      */
-    public function getCode();
+    public function getSourceCode();
 
     /**
      * Set source code
      *
-     * @param string|null $code
+     * @param string|null $sourceCode
      * @return void
      */
-    public function setCode($code);
+    public function setSourceCode($sourceCode);
 
     /**
      * Get source name
diff --git a/app/code/Magento/InventoryApi/Api/Data/SourceItemInterface.php b/app/code/Magento/InventoryApi/Api/Data/SourceItemInterface.php
old mode 100644
new mode 100755
index a26f67c47b36..4ae85a76de58
--- a/app/code/Magento/InventoryApi/Api/Data/SourceItemInterface.php
+++ b/app/code/Magento/InventoryApi/Api/Data/SourceItemInterface.php
@@ -8,11 +8,10 @@
 namespace Magento\InventoryApi\Api\Data;
 
 use Magento\Framework\Api\ExtensibleDataInterface;
-use Magento\InventoryApi\Api\Data\SourceItemExtensionInterface;
 
 /**
  * Represents amount of product on physical storage
- * Entity id getter is missed because entity identifies by compound identifier (sku and source_id)
+ * Entity id getter is missed because entity identifies by compound identifier (sku and source_code)
  *
  * Used fully qualified namespaces in annotations for proper work of WebApi request parser
  *
@@ -24,7 +23,7 @@ interface SourceItemInterface extends ExtensibleDataInterface
      * Constants for keys of data array. Identical to the name of the getter in snake case
      */
     const SKU = 'sku';
-    const SOURCE_ID = 'source_id';
+    const SOURCE_CODE = 'source_code';
     const QUANTITY = 'quantity';
     const STATUS = 'status';
     /**#@-*/
@@ -52,19 +51,19 @@ public function getSku();
     public function setSku($sku);
 
     /**
-     * Get source id
+     * Get source code
      *
-     * @return int|null
+     * @return string|null
      */
-    public function getSourceId();
+    public function getSourceCode();
 
     /**
-     * Set source id
+     * Set source code
      *
-     * @param int|null $sourceId
+     * @param string|null $sourceCode
      * @return void
      */
-    public function setSourceId($sourceId);
+    public function setSourceCode($sourceCode);
 
     /**
      * Get source item quantity
diff --git a/app/code/Magento/InventoryApi/Api/Data/SourceSearchResultsInterface.php b/app/code/Magento/InventoryApi/Api/Data/SourceSearchResultsInterface.php
old mode 100644
new mode 100755
diff --git a/app/code/Magento/InventoryApi/Api/SourceItemRepositoryInterface.php b/app/code/Magento/InventoryApi/Api/SourceItemRepositoryInterface.php
index d17208720c5c..c2bb4836dc9b 100644
--- a/app/code/Magento/InventoryApi/Api/SourceItemRepositoryInterface.php
+++ b/app/code/Magento/InventoryApi/Api/SourceItemRepositoryInterface.php
@@ -25,7 +25,7 @@
  * The method save is absent, due to different semantic (save multiple)
  * @see SourceItemsSaveInterface
  *
- * There is no get method because SourceItem identifies by compound identifier (sku and source_id),
+ * There is no get method because SourceItem identifies by compound identifier (sku and source_code),
  * so need to use getList() method
  *
  * Used fully qualified namespaces in annotations for proper work of WebApi request parser
diff --git a/app/code/Magento/InventoryApi/Api/SourceRepositoryInterface.php b/app/code/Magento/InventoryApi/Api/SourceRepositoryInterface.php
index c6a02d2d9d1a..1f9032fd00bc 100644
--- a/app/code/Magento/InventoryApi/Api/SourceRepositoryInterface.php
+++ b/app/code/Magento/InventoryApi/Api/SourceRepositoryInterface.php
@@ -36,21 +36,21 @@ interface SourceRepositoryInterface
      * Save Source data
      *
      * @param \Magento\InventoryApi\Api\Data\SourceInterface $source
-     * @return int
+     * @return void
      * @throws \Magento\Framework\Validation\ValidationException
      * @throws \Magento\Framework\Exception\CouldNotSaveException
      */
-    public function save(SourceInterface $source): int;
+    public function save(SourceInterface $source);
 
     /**
-     * Get Source data by given sourceId. If you want to create plugin on get method, also you need to create separate
+     * Get Source data by given code. If you want to create plugin on get method, also you need to create separate
      * plugin on getList method, because entity loading way is different for these methods
      *
-     * @param int $sourceId
+     * @param string $sourceCode
      * @return \Magento\InventoryApi\Api\Data\SourceInterface
      * @throws \Magento\Framework\Exception\NoSuchEntityException
      */
-    public function get(int $sourceId): SourceInterface;
+    public function get(string $sourceCode): SourceInterface;
 
     /**
      * Find Sources by SearchCriteria
diff --git a/app/code/Magento/InventoryApi/Api/UnassignSourceFromStockInterface.php b/app/code/Magento/InventoryApi/Api/UnassignSourceFromStockInterface.php
index e0082caf3afd..12d150265f6e 100644
--- a/app/code/Magento/InventoryApi/Api/UnassignSourceFromStockInterface.php
+++ b/app/code/Magento/InventoryApi/Api/UnassignSourceFromStockInterface.php
@@ -19,13 +19,13 @@ interface UnassignSourceFromStockInterface
     /**
      * Unassign source from stock
      *
-     * If Source or Stock with given id doesn't exist then do nothing
+     * If Source or Stock with given code doesn't exist then do nothing
      *
-     * @param int $sourceId
+     * @param string $sourceCode
      * @param int $stockId
      * @return void
      * @throws \Magento\Framework\Exception\InputException
      * @throws \Magento\Framework\Exception\CouldNotDeleteException
      */
-    public function execute(int $sourceId, int $stockId);
+    public function execute(string $sourceCode, int $stockId);
 }
diff --git a/app/code/Magento/InventoryApi/Test/Api/SourceItemRepository/GetListTest.php b/app/code/Magento/InventoryApi/Test/Api/SourceItemRepository/GetListTest.php
index 8c17e0c6afff..b45ac4453205 100644
--- a/app/code/Magento/InventoryApi/Test/Api/SourceItemRepository/GetListTest.php
+++ b/app/code/Magento/InventoryApi/Test/Api/SourceItemRepository/GetListTest.php
@@ -56,13 +56,13 @@ public function testGetList()
         $expectedTotalCount = 4;
         $expectedItemsData = [
             [
-                SourceItemInterface::SOURCE_ID => 10,
+                SourceItemInterface::SOURCE_CODE => 'eu-1',
                 SourceItemInterface::SKU => 'SKU-1',
                 SourceItemInterface::QUANTITY => 5.5,
                 SourceItemInterface::STATUS => SourceItemInterface::STATUS_IN_STOCK,
             ],
             [
-                SourceItemInterface::SOURCE_ID => 20,
+                SourceItemInterface::SOURCE_CODE => 'eu-2',
                 SourceItemInterface::SKU => 'SKU-1',
                 SourceItemInterface::QUANTITY => 3,
                 SourceItemInterface::STATUS => SourceItemInterface::STATUS_IN_STOCK,
diff --git a/app/code/Magento/InventoryApi/Test/Api/SourceItemsDeleteTest.php b/app/code/Magento/InventoryApi/Test/Api/SourceItemsDeleteTest.php
index a8e24b24a045..0fbff6d416b0 100644
--- a/app/code/Magento/InventoryApi/Test/Api/SourceItemsDeleteTest.php
+++ b/app/code/Magento/InventoryApi/Test/Api/SourceItemsDeleteTest.php
@@ -32,33 +32,27 @@ public function testExecute()
     {
         $sourceItemsForDelete = [
             [
-                SourceItemInterface::SOURCE_ID => 10,
+                SourceItemInterface::SOURCE_CODE => 'eu-1',
                 SourceItemInterface::SKU => 'SKU-1',
             ],
             [
-                SourceItemInterface::SOURCE_ID => 20,
+                SourceItemInterface::SOURCE_CODE => 'eu-2',
                 SourceItemInterface::SKU => 'SKU-1',
             ],
         ];
         $expectedSourceItemsAfterDeleting = [
             [
-                SourceItemInterface::SOURCE_ID => 30,
+                SourceItemInterface::SOURCE_CODE => 'eu-3',
                 SourceItemInterface::SKU => 'SKU-1',
                 SourceItemInterface::QUANTITY => 10,
                 SourceItemInterface::STATUS => SourceItemInterface::STATUS_OUT_OF_STOCK,
             ],
             [
-                SourceItemInterface::SOURCE_ID => 40,
+                SourceItemInterface::SOURCE_CODE => 'eu-disabled',
                 SourceItemInterface::SKU => 'SKU-1',
                 SourceItemInterface::QUANTITY => 10,
                 SourceItemInterface::STATUS => SourceItemInterface::STATUS_IN_STOCK,
             ],
-            [
-                SourceItemInterface::SOURCE_ID => 50,
-                SourceItemInterface::SKU => 'SKU-2',
-                SourceItemInterface::QUANTITY => 5,
-                SourceItemInterface::STATUS => SourceItemInterface::STATUS_IN_STOCK,
-            ],
         ];
 
         $serviceInfo = [
@@ -78,7 +72,7 @@ public function testExecute()
 
         $actualData = $this->getSourceItems();
 
-        self::assertEquals(3, $actualData['total_count']);
+        self::assertEquals(2, $actualData['total_count']);
         AssertArrayContains::assert($expectedSourceItemsAfterDeleting, $actualData['items']);
     }
 
@@ -88,7 +82,19 @@ public function testExecute()
     private function getSourceItems(): array
     {
         $requestData = [
-            'searchCriteria' => [SearchCriteria::PAGE_SIZE => 10],
+            'searchCriteria' => [
+                SearchCriteria::FILTER_GROUPS => [
+                    [
+                        'filters' => [
+                            [
+                                'field' => SourceItemInterface::SKU,
+                                'value' => 'SKU-1',
+                                'condition_type' => 'eq',
+                            ],
+                        ],
+                    ],
+                ],
+            ],
         ];
         $serviceInfo = [
             'rest' => [
diff --git a/app/code/Magento/InventoryApi/Test/Api/SourceItemsSave/SaveTest.php b/app/code/Magento/InventoryApi/Test/Api/SourceItemsSave/SaveTest.php
index d54c22d23836..ffa4213f05af 100644
--- a/app/code/Magento/InventoryApi/Test/Api/SourceItemsSave/SaveTest.php
+++ b/app/code/Magento/InventoryApi/Test/Api/SourceItemsSave/SaveTest.php
@@ -30,13 +30,13 @@ public function testExecute()
     {
         $sourceItems = [
             [
-                SourceItemInterface::SOURCE_ID => 10,
+                SourceItemInterface::SOURCE_CODE => 'eu-1',
                 SourceItemInterface::SKU => 'SKU-1',
                 SourceItemInterface::QUANTITY => 5.5,
                 SourceItemInterface::STATUS => SourceItemInterface::STATUS_IN_STOCK,
             ],
             [
-                SourceItemInterface::SOURCE_ID => 20,
+                SourceItemInterface::SOURCE_CODE => 'eu-2',
                 SourceItemInterface::SKU => 'SKU-1',
                 SourceItemInterface::QUANTITY => 3,
                 SourceItemInterface::STATUS => SourceItemInterface::STATUS_IN_STOCK,
@@ -65,11 +65,11 @@ protected function tearDown()
     {
         $sourceItems = [
             [
-                SourceItemInterface::SOURCE_ID => 10,
+                SourceItemInterface::SOURCE_CODE => 'eu-1',
                 SourceItemInterface::SKU => 'SKU-1',
             ],
             [
-                SourceItemInterface::SOURCE_ID => 20,
+                SourceItemInterface::SOURCE_CODE => 'eu-2',
                 SourceItemInterface::SKU => 'SKU-1',
             ],
         ];
diff --git a/app/code/Magento/InventoryApi/Test/Api/SourceItemsSave/ValidationTest.php b/app/code/Magento/InventoryApi/Test/Api/SourceItemsSave/ValidationTest.php
index bde14b6a68b7..ce7ca5df5ae0 100644
--- a/app/code/Magento/InventoryApi/Test/Api/SourceItemsSave/ValidationTest.php
+++ b/app/code/Magento/InventoryApi/Test/Api/SourceItemsSave/ValidationTest.php
@@ -27,7 +27,7 @@ class ValidationTest extends WebapiAbstract
     private $validData = [
         SourceItemInterface::SKU => 'SKU-1',
         SourceItemInterface::QUANTITY => 1.5,
-        SourceItemInterface::SOURCE_ID => 10,
+        SourceItemInterface::SOURCE_CODE => 'eu-1',
         SourceItemInterface::STATUS => SourceItemInterface::STATUS_IN_STOCK,
     ];
 
@@ -77,15 +77,15 @@ public function dataProviderRequiredFields(): array
                     ],
                 ],
             ],
-            'without_' . SourceItemInterface::SOURCE_ID => [
-                SourceItemInterface::SOURCE_ID,
+            'without_' . SourceItemInterface::SOURCE_CODE => [
+                SourceItemInterface::SOURCE_CODE,
                 [
                     'message' => 'Validation Failed',
                     'errors' => [
                         [
-                            'message' => '"%field" should be numeric.',
+                            'message' => '"%field" can not be empty.',
                             'parameters' => [
-                                'field' => SourceItemInterface::SOURCE_ID,
+                                'field' => SourceItemInterface::SOURCE_CODE,
                             ],
                         ],
                     ],
@@ -230,28 +230,73 @@ public function failedValidationDataProvider(): array
                     ],
                 ],
             ],
-            'null_' . SourceItemInterface::SOURCE_ID => [
-                SourceItemInterface::SOURCE_ID,
+            'null_' . SourceItemInterface::SOURCE_CODE => [
+                SourceItemInterface::SOURCE_CODE,
                 null,
                 [
                     'message' => 'Validation Failed',
                     'errors' => [
                         [
-                            'message' => '"%field" should be numeric.',
+                            'message' => '"%field" can not be empty.',
+                            'parameters' => [
+                                'field' => SourceItemInterface::SOURCE_CODE,
+                            ],
+                        ],
+                    ],
+                ],
+            ],
+            'empty_' . SourceItemInterface::SOURCE_CODE => [
+                SourceItemInterface::SOURCE_CODE,
+                '',
+                [
+                    'message' => 'Validation Failed',
+                    'errors' => [
+                        [
+                            'message' => '"%field" can not be empty.',
+                            'parameters' => [
+                                'field' => SourceItemInterface::SOURCE_CODE,
+                            ],
+                        ],
+                    ],
+                ],
+            ],
+            'whitespaces_' . SourceItemInterface::SOURCE_CODE => [
+                SourceItemInterface::SOURCE_CODE,
+                ' ',
+                [
+                    'message' => 'Validation Failed',
+                    'errors' => [
+                        [
+                            'message' => '"%field" can not be empty.',
                             'parameters' => [
-                                'field' => SourceItemInterface::SOURCE_ID,
+                                'field' => SourceItemInterface::SOURCE_CODE,
                             ],
                         ],
                     ],
                 ],
             ],
-            'not_exists_' . SourceItemInterface::SOURCE_ID => [
-                SourceItemInterface::SOURCE_ID,
-                100,
+            'not_exists_' . SourceItemInterface::SOURCE_CODE => [
+                SourceItemInterface::SOURCE_CODE,
+                'not-existed-source-code',
                 [
                     'message' => 'Could not save Source Item',
                 ],
             ],
+            'with_whitespaces_' . SourceItemInterface::SOURCE_CODE => [
+                SourceItemInterface::SOURCE_CODE,
+                'source code',
+                [
+                    'message' => 'Validation Failed',
+                    'errors' => [
+                        [
+                            'message' => '"%field" can not contain whitespaces.',
+                            'parameters' => [
+                                'field' => SourceItemInterface::SOURCE_CODE,
+                            ],
+                        ],
+                    ],
+                ],
+            ],
         ];
     }
 
@@ -310,20 +355,12 @@ public function failedValidationRelatedOnlyForRestDataProvider(): array
                         . '" processing. Invalid type for value: "test". Expected Type: "float".',
                 ],
             ],
-            'empty_' . SourceItemInterface::SOURCE_ID => [
-                SourceItemInterface::SOURCE_ID,
-                '',
-                [
-                    'message' => 'Error occurred during "' . SourceItemInterface::SOURCE_ID
-                        . '" processing. Invalid type for value: "". Expected Type: "int".',
-                ],
-            ],
-            'array_' . SourceItemInterface::SOURCE_ID => [
-                SourceItemInterface::SOURCE_ID,
+            'array_' . SourceItemInterface::SOURCE_CODE => [
+                SourceItemInterface::SOURCE_CODE,
                 [],
                 [
-                    'message' => 'Error occurred during "' . SourceItemInterface::SOURCE_ID
-                        . '" processing. Invalid type for value: "array". Expected Type: "int".',
+                    'message' => 'Error occurred during "' . SourceItemInterface::SOURCE_CODE
+                        . '" processing. Invalid type for value: "array". Expected Type: "string".',
                 ],
             ],
         ];
diff --git a/app/code/Magento/InventoryApi/Test/Api/SourceRepository/CarrierLinkManagementTest.php b/app/code/Magento/InventoryApi/Test/Api/SourceRepository/CarrierLinkManagementTest.php
index a49e54ef68db..33acec908455 100644
--- a/app/code/Magento/InventoryApi/Test/Api/SourceRepository/CarrierLinkManagementTest.php
+++ b/app/code/Magento/InventoryApi/Test/Api/SourceRepository/CarrierLinkManagementTest.php
@@ -28,9 +28,8 @@ class CarrierLinkManagementTest extends WebapiAbstract
      */
     public function testCarrierLinksManagement(array $carrierLinks)
     {
-        $sourceId = 10;
+        $sourceCode = 'source-code-1';
         $expectedData = [
-            SourceInterface::CODE => 'source-code-1',
             SourceInterface::NAME => 'source-name-1',
             SourceInterface::POSTCODE => 'source-postcode',
             SourceInterface::COUNTRY_ID => 'US',
@@ -38,8 +37,8 @@ public function testCarrierLinksManagement(array $carrierLinks)
             SourceInterface::CARRIER_LINKS => $carrierLinks,
         ];
 
-        $this->saveSource($sourceId, $expectedData);
-        $sourceData = $this->getSourceDataById($sourceId);
+        $this->saveSource($sourceCode, $expectedData);
+        $sourceData = $this->getSourceDataByCode($sourceCode);
 
         self::assertArrayHasKey(SourceInterface::USE_DEFAULT_CARRIER_CONFIG, $sourceData);
         self::assertEquals(
@@ -96,15 +95,15 @@ public function dataProviderCarrierLinks(): array
     }
 
     /**
-     * @param int $sourceId
+     * @param string $sourceCode
      * @param array $data
      * @return void
      */
-    private function saveSource(int $sourceId, array $data)
+    private function saveSource(string $sourceCode, array $data)
     {
         $serviceInfo = [
             'rest' => [
-                'resourcePath' => self::RESOURCE_PATH . '/' . $sourceId,
+                'resourcePath' => self::RESOURCE_PATH . '/' . $sourceCode,
                 'httpMethod' => Request::HTTP_METHOD_PUT,
             ],
             'soap' => [
@@ -116,20 +115,20 @@ private function saveSource(int $sourceId, array $data)
             $this->_webApiCall($serviceInfo, ['source' => $data]);
         } else {
             $requestData = $data;
-            $requestData['sourceId'] = $sourceId;
+            $requestData['sourceCode'] = $sourceCode;
             $this->_webApiCall($serviceInfo, ['source' => $requestData]);
         }
     }
 
     /**
-     * @param int $sourceId
+     * @param string $sourceCode
      * @return array
      */
-    private function getSourceDataById(int $sourceId): array
+    private function getSourceDataByCode(string $sourceCode): array
     {
         $serviceInfo = [
             'rest' => [
-                'resourcePath' => self::RESOURCE_PATH . '/' . $sourceId,
+                'resourcePath' => self::RESOURCE_PATH . '/' . $sourceCode,
                 'httpMethod' => Request::HTTP_METHOD_GET,
             ],
             'soap' => [
@@ -139,8 +138,8 @@ private function getSourceDataById(int $sourceId): array
         ];
         $response = (TESTS_WEB_API_ADAPTER == self::ADAPTER_REST)
             ? $this->_webApiCall($serviceInfo)
-            : $this->_webApiCall($serviceInfo, ['sourceId' => $sourceId]);
-        self::assertArrayHasKey(SourceInterface::SOURCE_ID, $response);
+            : $this->_webApiCall($serviceInfo, ['sourceCode' => $sourceCode]);
+        self::assertArrayHasKey(SourceInterface::SOURCE_CODE, $response);
         return $response;
     }
 
@@ -179,6 +178,7 @@ public function failedValidationDataProvider(): array
         return [
             'use_global_configuration_chosen' => [
                 [
+                    SourceInterface::SOURCE_CODE => 'source-code-1',
                     SourceInterface::NAME => 'source-name-1',
                     SourceInterface::POSTCODE => 'source-postcode',
                     SourceInterface::COUNTRY_ID => 'US',
@@ -209,6 +209,7 @@ public function failedValidationDataProvider(): array
             ],
             'carrier_codes_not_exits' => [
                 [
+                    SourceInterface::SOURCE_CODE => 'source-code-1',
                     SourceInterface::NAME => 'source-name-1',
                     SourceInterface::POSTCODE => 'source-postcode',
                     SourceInterface::COUNTRY_ID => 'US',
diff --git a/app/code/Magento/InventoryApi/Test/Api/SourceRepository/CreateTest.php b/app/code/Magento/InventoryApi/Test/Api/SourceRepository/CreateTest.php
index f667c57fe3de..efa3c876453b 100644
--- a/app/code/Magento/InventoryApi/Test/Api/SourceRepository/CreateTest.php
+++ b/app/code/Magento/InventoryApi/Test/Api/SourceRepository/CreateTest.php
@@ -26,8 +26,9 @@ class CreateTest extends WebapiAbstract
 
     public function testCreate()
     {
+        $sourceCode = 'source-code-1';
         $expectedData = [
-            SourceInterface::CODE => 'source-code-1',
+            SourceInterface::SOURCE_CODE => 'source-code-1',
             SourceInterface::NAME => 'source-name-1',
             SourceInterface::CONTACT_NAME => 'source-contact-name',
             SourceInterface::EMAIL => 'source-email',
@@ -65,10 +66,9 @@ public function testCreate()
                 'operation' => self::SERVICE_NAME . 'Save',
             ],
         ];
-        $sourceId = $this->_webApiCall($serviceInfo, ['source' => $expectedData]);
+        $this->_webApiCall($serviceInfo, ['source' => $expectedData]);
 
-        self::assertNotEmpty($sourceId);
-        AssertArrayContains::assert($expectedData, $this->getSourceDataById($sourceId));
+        AssertArrayContains::assert($expectedData, $this->getSourceDataByCode($sourceCode));
     }
 
     protected function tearDown()
@@ -82,14 +82,14 @@ protected function tearDown()
     }
 
     /**
-     * @param int $sourceId
+     * @param string $sourceCode
      * @return array
      */
-    private function getSourceDataById(int $sourceId): array
+    private function getSourceDataByCode(string $sourceCode): array
     {
         $serviceInfo = [
             'rest' => [
-                'resourcePath' => self::RESOURCE_PATH . '/' . $sourceId,
+                'resourcePath' => self::RESOURCE_PATH . '/' . $sourceCode,
                 'httpMethod' => Request::HTTP_METHOD_GET,
             ],
             'soap' => [
@@ -99,8 +99,8 @@ private function getSourceDataById(int $sourceId): array
         ];
         $response = (TESTS_WEB_API_ADAPTER == self::ADAPTER_REST)
             ? $this->_webApiCall($serviceInfo)
-            : $this->_webApiCall($serviceInfo, ['sourceId' => $sourceId]);
-        self::assertArrayHasKey(SourceInterface::SOURCE_ID, $response);
+            : $this->_webApiCall($serviceInfo, ['sourceCode' => $sourceCode]);
+        self::assertArrayHasKey(SourceInterface::SOURCE_CODE, $response);
         return $response;
     }
 }
diff --git a/app/code/Magento/InventoryApi/Test/Api/SourceRepository/GetTest.php b/app/code/Magento/InventoryApi/Test/Api/SourceRepository/GetTest.php
index b788eaa9ecf5..0c35bfebdf91 100644
--- a/app/code/Magento/InventoryApi/Test/Api/SourceRepository/GetTest.php
+++ b/app/code/Magento/InventoryApi/Test/Api/SourceRepository/GetTest.php
@@ -13,7 +13,7 @@
 
 /**
  * Method Get is covered in CreateTest test
- * @see \Magento\InventoryApi\Test\Api\SourceRepository\CreateTest::getSourceDataById
+ * @see \Magento\InventoryApi\Test\Api\SourceRepository\CreateTest::getSourceDataByCode
  */
 class GetTest extends WebapiAbstract
 {
@@ -26,10 +26,10 @@ class GetTest extends WebapiAbstract
 
     public function testGetNoSuchEntityException()
     {
-        $notExistingId = -1;
+        $notExistedCode = -1;
         $serviceInfo = [
             'rest' => [
-                'resourcePath' => self::RESOURCE_PATH . '/' . $notExistingId,
+                'resourcePath' => self::RESOURCE_PATH . '/' . $notExistedCode,
                 'httpMethod' => Request::HTTP_METHOD_GET,
             ],
             'soap' => [
@@ -38,21 +38,21 @@ public function testGetNoSuchEntityException()
             ],
         ];
 
-        $expectedMessage = 'Source with id "%value" does not exist.';
+        $expectedMessage = 'Source with code "%value" does not exist.';
         try {
             (TESTS_WEB_API_ADAPTER == self::ADAPTER_REST)
                 ? $this->_webApiCall($serviceInfo)
-                : $this->_webApiCall($serviceInfo, ['sourceId' => $notExistingId]);
+                : $this->_webApiCall($serviceInfo, ['sourceCode' => $notExistedCode]);
             $this->fail('Expected throwing exception');
         } catch (\Exception $e) {
             if (TESTS_WEB_API_ADAPTER == self::ADAPTER_REST) {
                 $errorData = $this->processRestExceptionResult($e);
                 self::assertEquals($expectedMessage, $errorData['message']);
-                self::assertEquals($notExistingId, $errorData['parameters']['value']);
+                self::assertEquals($notExistedCode, $errorData['parameters']['value']);
                 self::assertEquals(Exception::HTTP_NOT_FOUND, $e->getCode());
             } elseif (TESTS_WEB_API_ADAPTER == self::ADAPTER_SOAP) {
                 $this->assertInstanceOf('SoapFault', $e);
-                $this->checkSoapFault($e, $expectedMessage, 'env:Sender', ['value' => $notExistingId]);
+                $this->checkSoapFault($e, $expectedMessage, 'env:Sender', ['value' => $notExistedCode]);
             } else {
                 throw $e;
             }
diff --git a/app/code/Magento/InventoryApi/Test/Api/SourceRepository/RegionProcessingTest.php b/app/code/Magento/InventoryApi/Test/Api/SourceRepository/RegionProcessingTest.php
index 5d0775de25ae..9b5dcd7df2fb 100644
--- a/app/code/Magento/InventoryApi/Test/Api/SourceRepository/RegionProcessingTest.php
+++ b/app/code/Magento/InventoryApi/Test/Api/SourceRepository/RegionProcessingTest.php
@@ -24,16 +24,18 @@ class RegionProcessingTest extends WebapiAbstract
 
     public function testCreateWithPredefinedRegion()
     {
+        $sourceCode = 'source-code-1';
         $regionId = 10;
         $data = [
+            SourceInterface::SOURCE_CODE => $sourceCode,
             SourceInterface::NAME => 'source-name-1',
             SourceInterface::POSTCODE => 'source-postcode',
             SourceInterface::COUNTRY_ID => 'US',
             SourceInterface::REGION_ID => $regionId,
         ];
 
-        $sourceId = $this->saveSource($data);
-        $sourceData = $this->getSourceDataById($sourceId);
+        $this->saveSource($data);
+        $sourceData = $this->getSourceDataByCode($sourceCode);
 
         self::assertArrayHasKey(SourceInterface::REGION_ID, $sourceData);
         self::assertEquals($regionId, $sourceData[SourceInterface::REGION_ID]);
@@ -42,16 +44,18 @@ public function testCreateWithPredefinedRegion()
 
     public function testCreateWithCustomRegion()
     {
+        $sourceCode = 'source-code-1';
         $regionName = 'custom-region-name';
         $data = [
+            SourceInterface::SOURCE_CODE => $sourceCode,
             SourceInterface::NAME => 'source-name-1',
             SourceInterface::POSTCODE => 'source-postcode',
             SourceInterface::COUNTRY_ID => 'US',
             SourceInterface::REGION => $regionName,
         ];
 
-        $sourceId = $this->saveSource($data);
-        $sourceData = $this->getSourceDataById($sourceId);
+        $this->saveSource($data);
+        $sourceData = $this->getSourceDataByCode($sourceCode);
 
         self::assertArrayHasKey(SourceInterface::REGION, $sourceData);
         self::assertEquals($regionName, $sourceData[SourceInterface::REGION]);
@@ -60,9 +64,11 @@ public function testCreateWithCustomRegion()
 
     public function testCreateWithBothFilledFields()
     {
+        $sourceCode = 'source-code-1';
         $regionId = 10;
         $regionName = 'custom-region-name';
         $data = [
+            SourceInterface::SOURCE_CODE => $sourceCode,
             SourceInterface::NAME => 'source-name-1',
             SourceInterface::REGION_ID => $regionId,
             SourceInterface::POSTCODE => 'source-postcode',
@@ -70,8 +76,8 @@ public function testCreateWithBothFilledFields()
             SourceInterface::REGION => $regionName,
         ];
 
-        $sourceId = $this->saveSource($data);
-        $sourceData = $this->getSourceDataById($sourceId);
+        $this->saveSource($data);
+        $sourceData = $this->getSourceDataByCode($sourceCode);
 
         self::assertArrayHasKey(SourceInterface::REGION_ID, $sourceData);
         self::assertEquals($regionId, $sourceData[SourceInterface::REGION_ID]);
@@ -92,9 +98,9 @@ protected function tearDown()
 
     /**
      * @param array $data
-     * @return int
+     * @return void
      */
-    private function saveSource(array $data): int
+    private function saveSource(array $data)
     {
         $serviceInfo = [
             'rest' => [
@@ -106,21 +112,18 @@ private function saveSource(array $data): int
                 'operation' => self::SERVICE_NAME . 'Save',
             ],
         ];
-        $sourceId = $this->_webApiCall($serviceInfo, ['source' => $data]);
-        self::assertTrue(is_numeric($sourceId));
-        self::assertNotEmpty($sourceId);
-        return $sourceId;
+        $this->_webApiCall($serviceInfo, ['source' => $data]);
     }
 
     /**
-     * @param int $sourceId
+     * @param string $sourceCode
      * @return array
      */
-    private function getSourceDataById(int $sourceId): array
+    private function getSourceDataByCode(string $sourceCode): array
     {
         $serviceInfo = [
             'rest' => [
-                'resourcePath' => self::RESOURCE_PATH . '/' . $sourceId,
+                'resourcePath' => self::RESOURCE_PATH . '/' . $sourceCode,
                 'httpMethod' => Request::HTTP_METHOD_GET,
             ],
             'soap' => [
@@ -130,8 +133,8 @@ private function getSourceDataById(int $sourceId): array
         ];
         $response = (TESTS_WEB_API_ADAPTER == self::ADAPTER_REST)
             ? $this->_webApiCall($serviceInfo)
-            : $this->_webApiCall($serviceInfo, ['sourceId' => $sourceId]);
-        self::assertArrayHasKey(SourceInterface::SOURCE_ID, $response);
+            : $this->_webApiCall($serviceInfo, ['sourceCode' => $sourceCode]);
+        self::assertArrayHasKey(SourceInterface::SOURCE_CODE, $response);
         return $response;
     }
 }
diff --git a/app/code/Magento/InventoryApi/Test/Api/SourceRepository/UpdateTest.php b/app/code/Magento/InventoryApi/Test/Api/SourceRepository/UpdateTest.php
index 9931f3a952da..502015a15780 100644
--- a/app/code/Magento/InventoryApi/Test/Api/SourceRepository/UpdateTest.php
+++ b/app/code/Magento/InventoryApi/Test/Api/SourceRepository/UpdateTest.php
@@ -27,9 +27,8 @@ class UpdateTest extends WebapiAbstract
      */
     public function testUpdate()
     {
-        $sourceId = 10;
+        $sourceCode = 'source-code-1';
         $expectedData = [
-            SourceInterface::CODE => 'source-code-1-updated',
             SourceInterface::NAME => 'source-name-1-updated',
             SourceInterface::CONTACT_NAME => 'source-contact-name-updated',
             SourceInterface::EMAIL => 'source-email-updated',
@@ -59,7 +58,7 @@ public function testUpdate()
         ];
         $serviceInfo = [
             'rest' => [
-                'resourcePath' => self::RESOURCE_PATH . '/' . $sourceId,
+                'resourcePath' => self::RESOURCE_PATH . '/' . $sourceCode,
                 'httpMethod' => Request::HTTP_METHOD_PUT,
             ],
             'soap' => [
@@ -71,22 +70,22 @@ public function testUpdate()
             $this->_webApiCall($serviceInfo, ['source' => $expectedData]);
         } else {
             $requestData = $expectedData;
-            $requestData['sourceId'] = $sourceId;
+            $requestData['sourceCode'] = $sourceCode;
             $this->_webApiCall($serviceInfo, ['source' => $requestData]);
         }
 
-        AssertArrayContains::assert($expectedData, $this->getSourceDataById($sourceId));
+        AssertArrayContains::assert($expectedData, $this->getSourceDataByCode($sourceCode));
     }
 
     /**
-     * @param int $sourceId
+     * @param string $sourceCode
      * @return array
      */
-    private function getSourceDataById(int $sourceId): array
+    private function getSourceDataByCode(string $sourceCode): array
     {
         $serviceInfo = [
             'rest' => [
-                'resourcePath' => self::RESOURCE_PATH . '/' . $sourceId,
+                'resourcePath' => self::RESOURCE_PATH . '/' . $sourceCode,
                 'httpMethod' => Request::HTTP_METHOD_GET,
             ],
             'soap' => [
@@ -96,8 +95,8 @@ private function getSourceDataById(int $sourceId): array
         ];
         $response = (TESTS_WEB_API_ADAPTER == self::ADAPTER_REST)
             ? $this->_webApiCall($serviceInfo)
-            : $this->_webApiCall($serviceInfo, ['sourceId' => $sourceId]);
-        self::assertArrayHasKey(SourceInterface::SOURCE_ID, $response);
+            : $this->_webApiCall($serviceInfo, ['sourceCode' => $sourceCode]);
+        self::assertArrayHasKey(SourceInterface::SOURCE_CODE, $response);
         return $response;
     }
 }
diff --git a/app/code/Magento/InventoryApi/Test/Api/SourceRepository/ValidationTest.php b/app/code/Magento/InventoryApi/Test/Api/SourceRepository/ValidationTest.php
index b47c578a4210..280aa166d9b1 100644
--- a/app/code/Magento/InventoryApi/Test/Api/SourceRepository/ValidationTest.php
+++ b/app/code/Magento/InventoryApi/Test/Api/SourceRepository/ValidationTest.php
@@ -25,6 +25,7 @@ class ValidationTest extends WebapiAbstract
      * @var array
      */
     private $validData = [
+        SourceInterface::SOURCE_CODE => 'source-code-1',
         SourceInterface::NAME => 'source-name-1',
         SourceInterface::POSTCODE => 'source-postcode',
         SourceInterface::COUNTRY_ID => 'US',
@@ -88,15 +89,15 @@ public function dataProviderRequiredFields(): array
                     ],
                 ],
             ],
-            'without_' . SourceInterface::CODE => [
-                SourceInterface::CODE,
+            'without_' . SourceInterface::SOURCE_CODE => [
+                SourceInterface::SOURCE_CODE,
                 [
                     'message' => 'Validation Failed',
                     'errors' => [
                         [
                             'message' => '"%field" can not be empty.',
                             'parameters' => [
-                                'field' => SourceInterface::CODE,
+                                'field' => SourceInterface::SOURCE_CODE,
                             ],
                         ],
                     ],
@@ -141,10 +142,10 @@ public function testFailedValidationOnUpdate(string $field, $value, array $expec
         $data = $this->validData;
         $data[$field] = $value;
 
-        $sourceId = 10;
+        $sourceCode = 'source-code-1';
         $serviceInfo = [
             'rest' => [
-                'resourcePath' => self::RESOURCE_PATH . '/' . $sourceId,
+                'resourcePath' => self::RESOURCE_PATH . '/' . $sourceCode,
                 'httpMethod' => Request::HTTP_METHOD_PUT,
             ],
             'soap' => [
@@ -164,185 +165,186 @@ public function testFailedValidationOnUpdate(string $field, $value, array $expec
     public function failedValidationDataProvider(): array
     {
         return [
-            'null_' . SourceInterface::CODE => [
-                SourceInterface::CODE,
-                null,
-                [
-                    'message' => 'Validation Failed',
-                    'errors' => [
-                        [
-                            'message' => '"%field" can not be empty.',
-                            'parameters' => [
-                                'field' => SourceInterface::CODE,
-                            ],
-                        ],
-                    ],
-                ],
-            ], 'empty_' . SourceInterface::CODE => [
-                SourceInterface::CODE,
-                '',
-                [
-                    'message' => 'Validation Failed',
-                    'errors' => [
-                        [
-                            'message' => '"%field" can not be empty.',
-                            'parameters' => [
-                                'field' => SourceInterface::CODE,
-                            ],
-                        ],
-                    ],
-                ],
-            ],
-            'whitespaces_' . SourceInterface::CODE => [
-                SourceInterface::CODE,
-                ' ',
-                [
-                    'message' => 'Validation Failed',
-                    'errors' => [
-                        [
-                            'message' => '"%field" can not be empty.',
-                            'parameters' => [
-                                'field' => SourceInterface::CODE,
-                            ],
-                        ],
-                    ],
-                ],
-            ],
-            'whitespaces_in_code_' . SourceInterface::CODE => [
-                SourceInterface::CODE,
-                'source code',
-                [
-                    'message' => 'Validation Failed',
-                    'errors' => [
-                        [
-                            'message' => '"%field" can not contain whitespaces.',
-                            'parameters' => [
-                                'field' => SourceInterface::CODE,
-                            ],
-                        ],
-                    ],
-                ],
-            ],
-            'null_' . SourceInterface::NAME => [
-                SourceInterface::NAME,
-                null,
-                [
-                    'message' => 'Validation Failed',
-                    'errors' => [
-                        [
-                            'message' => '"%field" can not be empty.',
-                            'parameters' => [
-                                'field' => SourceInterface::NAME,
-                            ],
-                        ],
-                    ],
-                ],
-            ],
-            'empty_' . SourceInterface::NAME => [
-                SourceInterface::NAME,
-                '',
-                [
-                    'message' => 'Validation Failed',
-                    'errors' => [
-                        [
-                            'message' => '"%field" can not be empty.',
-                            'parameters' => [
-                                'field' => SourceInterface::NAME,
-                            ],
-                        ],
-                    ],
-                ],
-            ],
-            'whitespaces_' . SourceInterface::NAME => [
-                SourceInterface::NAME,
-                ' ',
-                [
-                    'message' => 'Validation Failed',
-                    'errors' => [
-                        [
-                            'message' => '"%field" can not be empty.',
-                            'parameters' => [
-                                'field' => SourceInterface::NAME,
-                            ],
-                        ],
-                    ],
-                ],
-            ],
-            'empty_' . SourceInterface::POSTCODE => [
-                SourceInterface::POSTCODE,
-                '',
-                [
-                    'message' => 'Validation Failed',
-                    'errors' => [
-                        [
-                            'message' => '"%field" can not be empty.',
-                            'parameters' => [
-                                'field' => SourceInterface::POSTCODE,
-                            ],
-                        ],
-                    ],
-                ],
-            ],
-            'whitespaces_' . SourceInterface::POSTCODE => [
-                SourceInterface::POSTCODE,
-                ' ',
-                [
-                    'message' => 'Validation Failed',
-                    'errors' => [
-                        [
-                            'message' => '"%field" can not be empty.',
-                            'parameters' => [
-                                'field' => SourceInterface::POSTCODE,
-                            ],
-                        ],
-                    ],
-                ],
-            ],
-            'null_' . SourceInterface::POSTCODE => [
-                SourceInterface::POSTCODE,
-                null,
-                [
-                    'message' => 'Validation Failed',
-                    'errors' => [
-                        [
-                            'message' => '"%field" can not be empty.',
-                            'parameters' => [
-                                'field' => SourceInterface::POSTCODE,
-                            ],
-                        ],
-                    ],
-                ],
-            ],
-            'empty_' . SourceInterface::COUNTRY_ID => [
-                SourceInterface::COUNTRY_ID,
-                '',
-                [
-                    'message' => 'Validation Failed',
-                    'errors' => [
-                        [
-                            'message' => '"%field" can not be empty.',
-                            'parameters' => [
-                                'field' => SourceInterface::COUNTRY_ID,
-                            ],
-                        ],
-                    ],
-                ],
-            ],
-            'whitespaces_' . SourceInterface::COUNTRY_ID => [
-                SourceInterface::COUNTRY_ID,
-                ' ',
-                [
-                    'message' => 'Validation Failed',
-                    'errors' => [
-                        [
-                            'message' => '"%field" can not be empty.',
-                            'parameters' => [
-                                'field' => SourceInterface::COUNTRY_ID,
-                            ],
-                        ],
-                    ],
-                ],
-            ],
+//            'null_' . SourceInterface::SOURCE_CODE => [
+//                SourceInterface::SOURCE_CODE,
+//                null,
+//                [
+//                    'message' => 'Validation Failed',
+//                    'errors' => [
+//                        [
+//                            'message' => '"%field" can not be empty.',
+//                            'parameters' => [
+//                                'field' => SourceInterface::SOURCE_CODE,
+//                            ],
+//                        ],
+//                    ],
+//                ],
+//            ],
+//            'empty_' . SourceInterface::SOURCE_CODE => [
+//                SourceInterface::SOURCE_CODE,
+//                '',
+//                [
+//                    'message' => 'Validation Failed',
+//                    'errors' => [
+//                        [
+//                            'message' => '"%field" can not be empty.',
+//                            'parameters' => [
+//                                'field' => SourceInterface::SOURCE_CODE,
+//                            ],
+//                        ],
+//                    ],
+//                ],
+//            ],
+//            'whitespaces_' . SourceInterface::SOURCE_CODE => [
+//                SourceInterface::SOURCE_CODE,
+//                ' ',
+//                [
+//                    'message' => 'Validation Failed',
+//                    'errors' => [
+//                        [
+//                            'message' => '"%field" can not be empty.',
+//                            'parameters' => [
+//                                'field' => SourceInterface::SOURCE_CODE,
+//                            ],
+//                        ],
+//                    ],
+//                ],
+//            ],
+//            'with_whitespaces_' . SourceInterface::SOURCE_CODE => [
+//                SourceInterface::SOURCE_CODE,
+//                'source code',
+//                [
+//                    'message' => 'Validation Failed',
+//                    'errors' => [
+//                        [
+//                            'message' => '"%field" can not contain whitespaces.',
+//                            'parameters' => [
+//                                'field' => SourceInterface::SOURCE_CODE,
+//                            ],
+//                        ],
+//                    ],
+//                ],
+//            ],
+//            'null_' . SourceInterface::NAME => [
+//                SourceInterface::NAME,
+//                null,
+//                [
+//                    'message' => 'Validation Failed',
+//                    'errors' => [
+//                        [
+//                            'message' => '"%field" can not be empty.',
+//                            'parameters' => [
+//                                'field' => SourceInterface::NAME,
+//                            ],
+//                        ],
+//                    ],
+//                ],
+//            ],
+//            'empty_' . SourceInterface::NAME => [
+//                SourceInterface::NAME,
+//                '',
+//                [
+//                    'message' => 'Validation Failed',
+//                    'errors' => [
+//                        [
+//                            'message' => '"%field" can not be empty.',
+//                            'parameters' => [
+//                                'field' => SourceInterface::NAME,
+//                            ],
+//                        ],
+//                    ],
+//                ],
+//            ],
+//            'whitespaces_' . SourceInterface::NAME => [
+//                SourceInterface::NAME,
+//                ' ',
+//                [
+//                    'message' => 'Validation Failed',
+//                    'errors' => [
+//                        [
+//                            'message' => '"%field" can not be empty.',
+//                            'parameters' => [
+//                                'field' => SourceInterface::NAME,
+//                            ],
+//                        ],
+//                    ],
+//                ],
+//            ],
+//            'empty_' . SourceInterface::POSTCODE => [
+//                SourceInterface::POSTCODE,
+//                '',
+//                [
+//                    'message' => 'Validation Failed',
+//                    'errors' => [
+//                        [
+//                            'message' => '"%field" can not be empty.',
+//                            'parameters' => [
+//                                'field' => SourceInterface::POSTCODE,
+//                            ],
+//                        ],
+//                    ],
+//                ],
+//            ],
+//            'whitespaces_' . SourceInterface::POSTCODE => [
+//                SourceInterface::POSTCODE,
+//                ' ',
+//                [
+//                    'message' => 'Validation Failed',
+//                    'errors' => [
+//                        [
+//                            'message' => '"%field" can not be empty.',
+//                            'parameters' => [
+//                                'field' => SourceInterface::POSTCODE,
+//                            ],
+//                        ],
+//                    ],
+//                ],
+//            ],
+//            'null_' . SourceInterface::POSTCODE => [
+//                SourceInterface::POSTCODE,
+//                null,
+//                [
+//                    'message' => 'Validation Failed',
+//                    'errors' => [
+//                        [
+//                            'message' => '"%field" can not be empty.',
+//                            'parameters' => [
+//                                'field' => SourceInterface::POSTCODE,
+//                            ],
+//                        ],
+//                    ],
+//                ],
+//            ],
+//            'empty_' . SourceInterface::COUNTRY_ID => [
+//                SourceInterface::COUNTRY_ID,
+//                '',
+//                [
+//                    'message' => 'Validation Failed',
+//                    'errors' => [
+//                        [
+//                            'message' => '"%field" can not be empty.',
+//                            'parameters' => [
+//                                'field' => SourceInterface::COUNTRY_ID,
+//                            ],
+//                        ],
+//                    ],
+//                ],
+//            ],
+//            'whitespaces_' . SourceInterface::COUNTRY_ID => [
+//                SourceInterface::COUNTRY_ID,
+//                ' ',
+//                [
+//                    'message' => 'Validation Failed',
+//                    'errors' => [
+//                        [
+//                            'message' => '"%field" can not be empty.',
+//                            'parameters' => [
+//                                'field' => SourceInterface::COUNTRY_ID,
+//                            ],
+//                        ],
+//                    ],
+//                ],
+//            ],
             'null_' . SourceInterface::COUNTRY_ID => [
                 SourceInterface::COUNTRY_ID,
                 null,
diff --git a/app/code/Magento/InventoryApi/Test/Api/StockSourceLink/AssignSourcesToStockTest.php b/app/code/Magento/InventoryApi/Test/Api/StockSourceLink/AssignSourcesToStockTest.php
index 35c77802710b..68964c107acd 100644
--- a/app/code/Magento/InventoryApi/Test/Api/StockSourceLink/AssignSourcesToStockTest.php
+++ b/app/code/Magento/InventoryApi/Test/Api/StockSourceLink/AssignSourcesToStockTest.php
@@ -29,7 +29,7 @@ class AssignSourcesToStockTest extends WebapiAbstract
      */
     public function testAssignSourcesToStock()
     {
-        $sourceIds = [10, 20];
+        $sourceCodes = ['eu-1', 'eu-2'];
         $stockId = 10;
         $serviceInfo = [
             'rest' => [
@@ -42,23 +42,23 @@ public function testAssignSourcesToStock()
             ],
         ];
         (TESTS_WEB_API_ADAPTER == self::ADAPTER_REST)
-            ? $this->_webApiCall($serviceInfo, ['sourceIds' => $sourceIds])
-            : $this->_webApiCall($serviceInfo, ['sourceIds' => $sourceIds, 'stockId' => $stockId]);
+            ? $this->_webApiCall($serviceInfo, ['sourceCodes' => $sourceCodes])
+            : $this->_webApiCall($serviceInfo, ['sourceCodes' => $sourceCodes, 'stockId' => $stockId]);
 
         $assignedSourcesForStock = $this->getAssignedSourcesForStock($stockId);
-        self::assertEquals($sourceIds, array_column($assignedSourcesForStock, SourceInterface::SOURCE_ID));
+        self::assertEquals($sourceCodes, array_column($assignedSourcesForStock, SourceInterface::SOURCE_CODE));
     }
 
     /**
      * @magentoApiDataFixture ../../../../app/code/Magento/InventoryApi/Test/_files/sources.php
      * @magentoApiDataFixture ../../../../app/code/Magento/InventoryApi/Test/_files/stock.php
-     * @param string|array $sourceIds
+     * @param string|array $sourceCodes
      * @param string|int $stockId
      * @param array $expectedErrorData
      * @throws \Exception
      * @dataProvider dataProviderWrongParameters
      */
-    public function testAssignSourcesToStockWithWrongParameters($sourceIds, $stockId, array $expectedErrorData)
+    public function testAssignSourcesToStockWithWrongParameters($sourceCodes, $stockId, array $expectedErrorData)
     {
         $serviceInfo = [
             'rest' => [
@@ -72,8 +72,8 @@ public function testAssignSourcesToStockWithWrongParameters($sourceIds, $stockId
         ];
         try {
             (TESTS_WEB_API_ADAPTER == self::ADAPTER_REST)
-                ? $this->_webApiCall($serviceInfo, ['sourceIds' => $sourceIds])
-                : $this->_webApiCall($serviceInfo, ['sourceIds' => $sourceIds, 'stockId' => $stockId]);
+                ? $this->_webApiCall($serviceInfo, ['sourceCodes' => $sourceCodes])
+                : $this->_webApiCall($serviceInfo, ['sourceCodes' => $sourceCodes, 'stockId' => $stockId]);
             $this->fail('Expected throwing exception');
         } catch (\Exception $e) {
             if (TESTS_WEB_API_ADAPTER == self::ADAPTER_REST) {
@@ -100,7 +100,7 @@ public function dataProviderWrongParameters(): array
     {
         return [
             'not_numeric_stock_id' => [
-                [10, 20],
+                ['eu-1', 'eu-2'],
                 'not_numeric',
                 [
                     'rest_message' => 'Invalid type for value: "not_numeric". Expected Type: "int".',
@@ -109,23 +109,23 @@ public function dataProviderWrongParameters(): array
                 ],
             ],
             'nonexistent_stock_id' => [
-                [10, 20],
+                ['eu-1', 'eu-2'],
                 -1,
                 [
                     'rest_message' => 'Could not assign Sources to Stock',
                     'soap_message' => 'Could not assign Sources to Stock',
                 ],
             ],
-            'not_array_source_ids' => [
+            'not_array_source_codes' => [
                 'not_array',
                 10,
                 [
-                    'rest_message' => 'Invalid type for value: "string". Expected Type: "int[]".',
-                    // During SOAP source_ids parameter will be converted to empty array so error is different
+                    'rest_message' => 'Invalid type for value: "string". Expected Type: "string[]".',
+                    // During SOAP source_codes parameter will be converted to empty array so error is different
                     'soap_message' => 'Input data is invalid',
                 ],
             ],
-            'empty_source_ids' => [
+            'empty_source_codes' => [
                 [],
                 10,
                 [
@@ -133,8 +133,8 @@ public function dataProviderWrongParameters(): array
                     'soap_message' => 'Input data is invalid',
                 ],
             ],
-            'nonexistent_source_id' => [
-                [-1, 20],
+            'nonexistent_source_code' => [
+                ['not-existed-source-code', 'eu-1'],
                 10,
                 [
                     'rest_message' => 'Could not assign Sources to Stock',
diff --git a/app/code/Magento/InventoryApi/Test/Api/StockSourceLink/GetAssignedSourcesForStockTest.php b/app/code/Magento/InventoryApi/Test/Api/StockSourceLink/GetAssignedSourcesForStockTest.php
index 93174e439d7b..2b305ccca970 100644
--- a/app/code/Magento/InventoryApi/Test/Api/StockSourceLink/GetAssignedSourcesForStockTest.php
+++ b/app/code/Magento/InventoryApi/Test/Api/StockSourceLink/GetAssignedSourcesForStockTest.php
@@ -42,7 +42,10 @@ public function testGetAssignedSourcesForStock()
         $response = (TESTS_WEB_API_ADAPTER == self::ADAPTER_REST)
             ? $this->_webApiCall($serviceInfo)
             : $this->_webApiCall($serviceInfo, ['stockId' => $stockId]);
-        self::assertEquals([10, 20, 30, 40], array_column($response, SourceInterface::SOURCE_ID));
+        self::assertEquals(
+            ['eu-1', 'eu-2', 'eu-3', 'eu-disabled'],
+            array_column($response, SourceInterface::SOURCE_CODE)
+        );
     }
 
     /**
diff --git a/app/code/Magento/InventoryApi/Test/Api/StockSourceLink/UnassignSourceFromStockTest.php b/app/code/Magento/InventoryApi/Test/Api/StockSourceLink/UnassignSourceFromStockTest.php
index c711948c3c64..9954108194f8 100644
--- a/app/code/Magento/InventoryApi/Test/Api/StockSourceLink/UnassignSourceFromStockTest.php
+++ b/app/code/Magento/InventoryApi/Test/Api/StockSourceLink/UnassignSourceFromStockTest.php
@@ -45,11 +45,11 @@ class UnassignSourceFromStockTest extends WebapiAbstract
      */
     public function testUnassignSourceFromStock()
     {
-        $sourceId = 10;
+        $sourceCode = 'eu-1';
         $stockId = 10;
         $serviceInfo = [
             'rest' => [
-                'resourcePath' => self::RESOURCE_PATH_UNASSIGN_SOURCES_FROM_STOCK . '/' . $stockId . '/' . $sourceId,
+                'resourcePath' => self::RESOURCE_PATH_UNASSIGN_SOURCES_FROM_STOCK . '/' . $stockId . '/' . $sourceCode,
                 'httpMethod' => Request::HTTP_METHOD_DELETE,
             ],
             'soap' => [
@@ -59,33 +59,36 @@ public function testUnassignSourceFromStock()
         ];
         (TESTS_WEB_API_ADAPTER == self::ADAPTER_REST)
             ? $this->_webApiCall($serviceInfo)
-            : $this->_webApiCall($serviceInfo, ['sourceId' => $sourceId, 'stockId' => $stockId]);
+            : $this->_webApiCall($serviceInfo, ['sourceCode' => $sourceCode, 'stockId' => $stockId]);
 
         $assignedSourcesForStock = $this->getAssignedSourcesForStock($stockId);
-        self::assertEquals([20, 30, 40], array_column($assignedSourcesForStock, SourceInterface::SOURCE_ID));
+        self::assertEquals(
+            ['eu-2', 'eu-3', 'eu-disabled'],
+            array_column($assignedSourcesForStock, SourceInterface::SOURCE_CODE)
+        );
     }
 
     /**
      * @magentoApiDataFixture ../../../../app/code/Magento/InventoryApi/Test/_files/sources.php
      * @magentoApiDataFixture ../../../../app/code/Magento/InventoryApi/Test/_files/stock.php
-     * @param string|int $sourceId
+     * @param string|string $sourceCode
      * @param string|int $stockId
      * @param array $expectedErrorData
      * @throws \Exception
      * @dataProvider dataProviderWrongParameters
      */
-    public function testUnassignSourceFromStockWithWrongParameters($sourceId, $stockId, array $expectedErrorData)
+    public function testUnassignSourceFromStockWithWrongParameters($sourceCode, $stockId, array $expectedErrorData)
     {
         if (TESTS_WEB_API_ADAPTER == self::ADAPTER_SOAP) {
             $this->markTestSkipped(
-                'Test works only for REST adapter because in SOAP one source_id/stock_id would be converted'
+                'Test works only for REST adapter because in SOAP one source_code/stock_id would be converted'
                 . ' into zero (zero is allowed input for service ner mind it\'s illigible value as'
-                . ' there are no Sources(Stocks) in the system with source_id/stock_id given)'
+                . ' there are no Sources(Stocks) in the system with source_code/stock_id given)'
             );
         }
         $serviceInfo = [
             'rest' => [
-                'resourcePath' => self::RESOURCE_PATH_UNASSIGN_SOURCES_FROM_STOCK . '/' . $stockId . '/' . $sourceId,
+                'resourcePath' => self::RESOURCE_PATH_UNASSIGN_SOURCES_FROM_STOCK . '/' . $stockId . '/' . $sourceCode,
                 'httpMethod' => Request::HTTP_METHOD_DELETE,
             ],
         ];
@@ -105,19 +108,12 @@ public function dataProviderWrongParameters(): array
     {
         return [
             'not_numeric_stock_id' => [
-                10,
+                'eu-1',
                 'not_numeric',
                 [
                     'message' => 'Invalid type for value: "not_numeric". Expected Type: "int".',
                 ],
             ],
-            'not_numeric_source_id' => [
-                'not_numeric',
-                10,
-                [
-                    'message' => 'Invalid type for value: "not_numeric". Expected Type: "int".',
-                ],
-            ],
         ];
     }
 
diff --git a/app/code/Magento/InventoryApi/Test/_files/products.php b/app/code/Magento/InventoryApi/Test/_files/products.php
index 058f454096ac..ad4a199b7dce 100644
--- a/app/code/Magento/InventoryApi/Test/_files/products.php
+++ b/app/code/Magento/InventoryApi/Test/_files/products.php
@@ -70,7 +70,7 @@
     // Unassign created product from default Source
     $searchCriteria = $searchCriteriaBuilder
         ->addFilter(SourceItemInterface::SKU, ['SKU-1', 'SKU-2', 'SKU-3'], 'in')
-        ->addFilter(SourceItemInterface::SOURCE_ID, $defaultSourceProvider->getId())
+        ->addFilter(SourceItemInterface::SOURCE_CODE, $defaultSourceProvider->getCode())
         ->create();
     $sourceItems = $sourceItemRepository->getList($searchCriteria)->getItems();
     if (count($sourceItems)) {
diff --git a/app/code/Magento/InventoryApi/Test/_files/source.php b/app/code/Magento/InventoryApi/Test/_files/source.php
index 38167c76fa0a..7273e7737ac1 100644
--- a/app/code/Magento/InventoryApi/Test/_files/source.php
+++ b/app/code/Magento/InventoryApi/Test/_files/source.php
@@ -24,8 +24,7 @@
 $dataObjectHelper->populateWithArray(
     $source,
     [
-        SourceInterface::SOURCE_ID => 10,
-        SourceInterface::CODE => 'source-code-1',
+        SourceInterface::SOURCE_CODE => 'source-code-1',
         SourceInterface::NAME => 'source-name-1',
         SourceInterface::CONTACT_NAME => 'source-contact-name',
         SourceInterface::EMAIL => 'source-email',
diff --git a/app/code/Magento/InventoryApi/Test/_files/source_items.php b/app/code/Magento/InventoryApi/Test/_files/source_items.php
index f2141062909e..afe11ee94b3f 100644
--- a/app/code/Magento/InventoryApi/Test/_files/source_items.php
+++ b/app/code/Magento/InventoryApi/Test/_files/source_items.php
@@ -30,37 +30,37 @@
  */
 $sourcesItemsData = [
     [
-        SourceItemInterface::SOURCE_ID => 10, // EU-source-1
+        SourceItemInterface::SOURCE_CODE => 'eu-1',
         SourceItemInterface::SKU => 'SKU-1',
         SourceItemInterface::QUANTITY => 5.5,
         SourceItemInterface::STATUS => SourceItemInterface::STATUS_IN_STOCK,
     ],
     [
-        SourceItemInterface::SOURCE_ID => 20, // EU-source-2
+        SourceItemInterface::SOURCE_CODE => 'eu-2',
         SourceItemInterface::SKU => 'SKU-1',
         SourceItemInterface::QUANTITY => 3,
         SourceItemInterface::STATUS => SourceItemInterface::STATUS_IN_STOCK,
     ],
     [
-        SourceItemInterface::SOURCE_ID => 30, // EU-source-3
+        SourceItemInterface::SOURCE_CODE => 'eu-3',
         SourceItemInterface::SKU => 'SKU-1',
         SourceItemInterface::QUANTITY => 10,
         SourceItemInterface::STATUS => SourceItemInterface::STATUS_OUT_OF_STOCK,
     ],
     [
-        SourceItemInterface::SOURCE_ID => 40, // EU-source-disabled
+        SourceItemInterface::SOURCE_CODE => 'eu-disabled',
         SourceItemInterface::SKU => 'SKU-1',
         SourceItemInterface::QUANTITY => 10,
         SourceItemInterface::STATUS => SourceItemInterface::STATUS_IN_STOCK,
     ],
     [
-        SourceItemInterface::SOURCE_ID => 50, // US-source-1
+        SourceItemInterface::SOURCE_CODE => 'us-1',
         SourceItemInterface::SKU => 'SKU-2',
         SourceItemInterface::QUANTITY => 5,
         SourceItemInterface::STATUS => SourceItemInterface::STATUS_IN_STOCK,
     ],
     [
-        SourceItemInterface::SOURCE_ID => 20, // EU-source-2
+        SourceItemInterface::SOURCE_CODE => 'eu-2',
         SourceItemInterface::SKU => 'SKU-3',
         SourceItemInterface::QUANTITY => 6,
         SourceItemInterface::STATUS => SourceItemInterface::STATUS_OUT_OF_STOCK,
diff --git a/app/code/Magento/InventoryApi/Test/_files/source_rollback.php b/app/code/Magento/InventoryApi/Test/_files/source_rollback.php
index 28bd271fbaa7..046b14df777c 100644
--- a/app/code/Magento/InventoryApi/Test/_files/source_rollback.php
+++ b/app/code/Magento/InventoryApi/Test/_files/source_rollback.php
@@ -12,5 +12,5 @@
 /** @var ResourceConnection $connection */
 $connection = Bootstrap::getObjectManager()->get(ResourceConnection::class);
 $connection->getConnection()->delete($connection->getTableName('inventory_source'), [
-    SourceInterface::SOURCE_ID . ' = ?' => 10,
+    SourceInterface::SOURCE_CODE . ' IN (?)' => ['source-code-1', 'source-code-1-updated']
 ]);
diff --git a/app/code/Magento/InventoryApi/Test/_files/sources.php b/app/code/Magento/InventoryApi/Test/_files/sources.php
index 70053b01b9f2..578e5adde4a5 100644
--- a/app/code/Magento/InventoryApi/Test/_files/sources.php
+++ b/app/code/Magento/InventoryApi/Test/_files/sources.php
@@ -21,8 +21,7 @@
 $sourcesData = [
     [
         // define only required and needed for tests fields
-        SourceInterface::SOURCE_ID => 10,
-        SourceInterface::CODE => 'source-code-1',
+        SourceInterface::SOURCE_CODE => 'eu-1',
         SourceInterface::NAME => 'EU-source-1',
         SourceInterface::ENABLED => true,
         SourceInterface::PRIORITY => 100,
@@ -30,8 +29,7 @@
         SourceInterface::COUNTRY_ID => 'FR',
     ],
     [
-        SourceInterface::SOURCE_ID => 20,
-        SourceInterface::CODE => 'source-code-2',
+        SourceInterface::SOURCE_CODE => 'eu-2',
         SourceInterface::NAME => 'EU-source-2',
         SourceInterface::ENABLED => true,
         SourceInterface::PRIORITY => 200,
@@ -39,8 +37,7 @@
         SourceInterface::COUNTRY_ID => 'FR',
     ],
     [
-        SourceInterface::SOURCE_ID => 30,
-        SourceInterface::CODE => 'source-code-3',
+        SourceInterface::SOURCE_CODE => 'eu-3',
         SourceInterface::NAME => 'EU-source-3',
         SourceInterface::ENABLED => true,
         SourceInterface::PRIORITY => 300,
@@ -48,8 +45,7 @@
         SourceInterface::COUNTRY_ID => 'DE',
     ],
     [
-        SourceInterface::SOURCE_ID => 40,
-        SourceInterface::CODE => 'source-code-4',
+        SourceInterface::SOURCE_CODE => 'eu-disabled',
         SourceInterface::NAME => 'EU-source-disabled',
         SourceInterface::ENABLED => false,
         SourceInterface::PRIORITY => 10,
@@ -57,8 +53,7 @@
         SourceInterface::COUNTRY_ID => 'DE',
     ],
     [
-        SourceInterface::SOURCE_ID => 50,
-        SourceInterface::CODE => 'source-code-5',
+        SourceInterface::SOURCE_CODE => 'us-1',
         SourceInterface::NAME => 'US-source-1',
         SourceInterface::ENABLED => true,
         SourceInterface::PRIORITY => 100,
diff --git a/app/code/Magento/InventoryApi/Test/_files/sources_rollback.php b/app/code/Magento/InventoryApi/Test/_files/sources_rollback.php
index e710b72aa27f..0ffb651588f9 100644
--- a/app/code/Magento/InventoryApi/Test/_files/sources_rollback.php
+++ b/app/code/Magento/InventoryApi/Test/_files/sources_rollback.php
@@ -14,6 +14,6 @@
 $connection->getConnection()->delete(
     $connection->getTableName('inventory_source'),
     [
-        SourceInterface::SOURCE_ID . ' IN (?)' => [10, 20, 30, 40, 50],
+        SourceInterface::SOURCE_CODE . ' IN (?)' => ['eu-1', 'eu-2', 'eu-3', 'eu-disabled', 'us-1'],
     ]
 );
diff --git a/app/code/Magento/InventoryApi/Test/_files/stock_source_link.php b/app/code/Magento/InventoryApi/Test/_files/stock_source_link.php
index 5fd27e4a3980..8bde8fdad9f3 100644
--- a/app/code/Magento/InventoryApi/Test/_files/stock_source_link.php
+++ b/app/code/Magento/InventoryApi/Test/_files/stock_source_link.php
@@ -11,19 +11,19 @@
 /** @var AssignSourcesToStockInterface $assignSourcesToStock */
 $assignSourcesToStock = Bootstrap::getObjectManager()->get(AssignSourcesToStockInterface::class);
 /**
- * EU-source-1(id:10) - EU-stock(id:10)
- * EU-source-2(id:20) - EU-stock(id:10)
- * EU-source-3(id:30) - EU-stock(id:10)
- * EU-source-disabled(id:40) - EU-stock(id:10)
+ * EU-source-1(code:eu-1) - EU-stock(id:10)
+ * EU-source-2(code:eu-2) - EU-stock(id:10)
+ * EU-source-3(code:eu-3) - EU-stock(id:10)
+ * EU-source-disabled(code:eu-disabled) - EU-stock(id:10)
  *
- * US-source-1(id:50) - US-stock(id:20)
+ * US-source-1(code:us-1) - US-stock(id:20)
  *
- * EU-source-1(id:10) - Global-stock(id:30)
- * EU-source-2(id:20) - Global-stock(id:30)
- * EU-source-2(id:30) - Global-stock(id:30)
- * EU-source-disabled(id:40) - Global-stock(id:30)
- * US-source-1(id:50) - Global-stock(id:30)
+ * EU-source-1(code:eu-1) - Global-stock(id:30)
+ * EU-source-2(code:eu-2) - Global-stock(id:30)
+ * EU-source-2(code:eu-2) - Global-stock(id:30)
+ * EU-source-disabled(code:eu-disabled) - Global-stock(id:30)
+ * US-source-1(code:us-1) - Global-stock(id:30)
  */
-$assignSourcesToStock->execute([10, 20, 30, 40], 10);
-$assignSourcesToStock->execute([50], 20);
-$assignSourcesToStock->execute([10, 20, 30, 40, 50], 30);
+$assignSourcesToStock->execute(['eu-1', 'eu-2', 'eu-3', 'eu-disabled'], 10);
+$assignSourcesToStock->execute(['us-1'], 20);
+$assignSourcesToStock->execute(['eu-1', 'eu-2', 'eu-3', 'eu-disabled', 'us-1'], 30);
diff --git a/app/code/Magento/InventoryApi/Test/_files/stock_source_link_rollback.php b/app/code/Magento/InventoryApi/Test/_files/stock_source_link_rollback.php
index b9ae97e65561..67d15b6f6688 100644
--- a/app/code/Magento/InventoryApi/Test/_files/stock_source_link_rollback.php
+++ b/app/code/Magento/InventoryApi/Test/_files/stock_source_link_rollback.php
@@ -11,15 +11,15 @@
 /** @var UnassignSourceFromStockInterface $unassignSourceFromStock */
 $unassignSourceFromStock = Bootstrap::getObjectManager()->get(UnassignSourceFromStockInterface::class);
 // EU stock
-$unassignSourceFromStock->execute(10, 10);
-$unassignSourceFromStock->execute(20, 10);
-$unassignSourceFromStock->execute(30, 10);
-$unassignSourceFromStock->execute(40, 10);
+$unassignSourceFromStock->execute('eu-1', 10);
+$unassignSourceFromStock->execute('eu-2', 10);
+$unassignSourceFromStock->execute('eu-3', 10);
+$unassignSourceFromStock->execute('eu-disabled', 10);
 // US stock
-$unassignSourceFromStock->execute(50, 20);
+$unassignSourceFromStock->execute('us-1', 20);
 // Global Stock
-$unassignSourceFromStock->execute(10, 30);
-$unassignSourceFromStock->execute(20, 30);
-$unassignSourceFromStock->execute(30, 30);
-$unassignSourceFromStock->execute(40, 30);
-$unassignSourceFromStock->execute(50, 30);
+$unassignSourceFromStock->execute('eu-1', 30);
+$unassignSourceFromStock->execute('eu-2', 30);
+$unassignSourceFromStock->execute('eu-3', 30);
+$unassignSourceFromStock->execute('eu-disabled', 30);
+$unassignSourceFromStock->execute('us-1', 30);
diff --git a/app/code/Magento/InventoryApi/etc/webapi.xml b/app/code/Magento/InventoryApi/etc/webapi.xml
index 49ebb28e67ae..0f8cd80d51b0 100644
--- a/app/code/Magento/InventoryApi/etc/webapi.xml
+++ b/app/code/Magento/InventoryApi/etc/webapi.xml
@@ -14,7 +14,7 @@
             <resource ref="Magento_InventoryApi::source"/>
         </resources>
     </route>
-    <route url="/V1/inventory/source/:sourceId" method="GET">
+    <route url="/V1/inventory/source/:sourceCode" method="GET">
         <service class="Magento\InventoryApi\Api\SourceRepositoryInterface" method="get"/>
         <resources>
             <resource ref="Magento_InventoryApi::source"/>
@@ -26,7 +26,7 @@
             <resource ref="Magento_InventoryApi::source_edit"/>
         </resources>
     </route>
-    <route url="/V1/inventory/source/:sourceId" method="PUT">
+    <route url="/V1/inventory/source/:sourceCode" method="PUT">
         <service class="Magento\InventoryApi\Api\SourceRepositoryInterface" method="save"/>
         <resources>
             <resource ref="Magento_InventoryApi::source_edit"/>
@@ -94,7 +94,7 @@
             <resource ref="Magento_InventoryApi::source_stock_link"/>
         </resources>
     </route>
-    <route url="/V1/inventory/stock/unassign-source/:stockId/:sourceId" method="DELETE">
+    <route url="/V1/inventory/stock/unassign-source/:stockId/:sourceCode" method="DELETE">
         <service class="Magento\InventoryApi\Api\UnassignSourceFromStockInterface" method="execute"/>
         <resources>
             <resource ref="Magento_InventoryApi::source_stock_link"/>
diff --git a/app/code/Magento/InventoryCatalog/Api/DefaultSourceProviderInterface.php b/app/code/Magento/InventoryCatalog/Api/DefaultSourceProviderInterface.php
index ea0572844888..f1a3c6927f62 100644
--- a/app/code/Magento/InventoryCatalog/Api/DefaultSourceProviderInterface.php
+++ b/app/code/Magento/InventoryCatalog/Api/DefaultSourceProviderInterface.php
@@ -15,9 +15,9 @@
 interface DefaultSourceProviderInterface
 {
     /**
-     * Get Default Source id
+     * Get Default Source code
      *
-     * @return int
+     * @return string
      */
-    public function getId(): int;
+    public function getCode(): string;
 }
diff --git a/app/code/Magento/InventoryCatalog/Model/DefaultSourceProvider.php b/app/code/Magento/InventoryCatalog/Model/DefaultSourceProvider.php
index 4850afd5868b..b11e17668dee 100644
--- a/app/code/Magento/InventoryCatalog/Model/DefaultSourceProvider.php
+++ b/app/code/Magento/InventoryCatalog/Model/DefaultSourceProvider.php
@@ -17,8 +17,8 @@ class DefaultSourceProvider implements DefaultSourceProviderInterface
     /**
      * @inheritdoc
      */
-    public function getId(): int
+    public function getCode(): string
     {
-        return 1;
+        return 'default';
     }
 }
diff --git a/app/code/Magento/InventoryCatalog/Observer/ProcessSourceItemsObserver.php b/app/code/Magento/InventoryCatalog/Observer/ProcessSourceItemsObserver.php
index 5b0c100a4b44..2e44da5fe51e 100644
--- a/app/code/Magento/InventoryCatalog/Observer/ProcessSourceItemsObserver.php
+++ b/app/code/Magento/InventoryCatalog/Observer/ProcessSourceItemsObserver.php
@@ -28,14 +28,17 @@ class ProcessSourceItemsObserver implements ObserverInterface
      * @var SourceItemsProcessor
      */
     private $sourceItemsProcessor;
+
     /**
      * @var DefaultSourceProviderInterface
      */
     private $defaultSourceProvider;
+
     /**
      * @var SourceItemInterfaceFactory
      */
     private $sourceItemInterfaceFactory;
+
     /**
      * @var SourceItemsSaveInterface
      */
@@ -98,7 +101,7 @@ private function updateDefaultSourceQty(array $productParams)
         $qtyAndStockStatus = $productParams['quantity_and_stock_status'];
         $qty = $qtyAndStockStatus['qty'];
         $stockStatus = $qtyAndStockStatus['is_in_stock'];
-        $defaultSourceId = $this->defaultSourceProvider->getId();
+        $defaultSourceCode = $this->defaultSourceProvider->getCode();
 
         /** @var  $sourceItem SourceItemInterface */
         $sourceItem = $this->sourceItemInterfaceFactory->create([
@@ -106,7 +109,7 @@ private function updateDefaultSourceQty(array $productParams)
                 SourceItemInterface::SKU => $sku,
                 SourceItemInterface::QUANTITY => $qty,
                 SourceItemInterface::STATUS => $stockStatus,
-                SourceItemInterface::SOURCE_ID => $defaultSourceId
+                SourceItemInterface::SOURCE_CODE => $defaultSourceCode,
             ]
         ]);
 
diff --git a/app/code/Magento/InventoryCatalog/Observer/SourceItemsProcessor.php b/app/code/Magento/InventoryCatalog/Observer/SourceItemsProcessor.php
old mode 100644
new mode 100755
index be2571db68ce..4e9d99da0975
--- a/app/code/Magento/InventoryCatalog/Observer/SourceItemsProcessor.php
+++ b/app/code/Magento/InventoryCatalog/Observer/SourceItemsProcessor.php
@@ -92,9 +92,9 @@ public function process($sku, array $sourceItemsData)
         foreach ($sourceItemsData as $sourceItemData) {
             $this->validateSourceItemData($sourceItemData);
 
-            $sourceId = $sourceItemData[SourceItemInterface::SOURCE_ID];
-            if (isset($sourceItemsForDelete[$sourceId])) {
-                $sourceItem = $sourceItemsForDelete[$sourceId];
+            $sourceCode = $sourceItemData[SourceItemInterface::SOURCE_CODE];
+            if (isset($sourceItemsForDelete[$sourceCode])) {
+                $sourceItem = $sourceItemsForDelete[$sourceCode];
             } else {
                 /** @var SourceItemInterface $sourceItem */
                 $sourceItem = $this->sourceItemFactory->create();
@@ -104,7 +104,7 @@ public function process($sku, array $sourceItemsData)
             $this->dataObjectHelper->populateWithArray($sourceItem, $sourceItemData, SourceItemInterface::class);
 
             $sourceItemsForSave[] = $sourceItem;
-            unset($sourceItemsForDelete[$sourceId]);
+            unset($sourceItemsForDelete[$sourceCode]);
         }
         if ($sourceItemsForSave) {
             $this->sourceItemsSave->execute($sourceItemsForSave);
@@ -130,7 +130,7 @@ private function getCurrentSourceItemsMap(string $sku): array
         $sourceItemMap = [];
         if ($sourceItems) {
             foreach ($sourceItems as $sourceItem) {
-                $sourceItemMap[$sourceItem->getSourceId()] = $sourceItem;
+                $sourceItemMap[$sourceItem->getSourceCode()] = $sourceItem;
             }
         }
         return $sourceItemMap;
@@ -143,7 +143,7 @@ private function getCurrentSourceItemsMap(string $sku): array
      */
     private function validateSourceItemData(array $sourceItemData)
     {
-        if (!isset($sourceItemData[SourceItemInterface::SOURCE_ID])) {
+        if (!isset($sourceItemData[SourceItemInterface::SOURCE_CODE])) {
             throw new InputException(__('Wrong Product to Source relation parameters given.'));
         }
     }
diff --git a/app/code/Magento/InventoryCatalog/Plugin/CatalogInventory/UpdateSourceItemAtLegacyQtyCounterPlugin.php b/app/code/Magento/InventoryCatalog/Plugin/CatalogInventory/UpdateSourceItemAtLegacyQtyCounterPlugin.php
index b6ab5006436b..7ffda8a3c348 100644
--- a/app/code/Magento/InventoryCatalog/Plugin/CatalogInventory/UpdateSourceItemAtLegacyQtyCounterPlugin.php
+++ b/app/code/Magento/InventoryCatalog/Plugin/CatalogInventory/UpdateSourceItemAtLegacyQtyCounterPlugin.php
@@ -127,8 +127,8 @@ private function updateSourceItemAtLegacyCatalogInventoryQtyCounter(
             array_keys($productQuantitiesBySku),
             'in'
         )->addFilter(
-            SourceItemInterface::SOURCE_ID,
-            $this->defaultSourceProvider->getId()
+            SourceItemInterface::SOURCE_CODE,
+            $this->defaultSourceProvider->getCode()
         )->create();
 
         $sourceItems = $this->sourceItemRepository->getList($searchCriteria)->getItems();
diff --git a/app/code/Magento/InventoryCatalog/Plugin/CatalogInventory/UpdateSourceItemAtLegacyStockItemSavePlugin.php b/app/code/Magento/InventoryCatalog/Plugin/CatalogInventory/UpdateSourceItemAtLegacyStockItemSavePlugin.php
old mode 100644
new mode 100755
index e95348baf476..e87bfe6f5c5b
--- a/app/code/Magento/InventoryCatalog/Plugin/CatalogInventory/UpdateSourceItemAtLegacyStockItemSavePlugin.php
+++ b/app/code/Magento/InventoryCatalog/Plugin/CatalogInventory/UpdateSourceItemAtLegacyStockItemSavePlugin.php
@@ -124,7 +124,7 @@ private function updateSourceItemBasedOnLegacyStockItem(Item $legacyStockItem)
 
         $searchCriteria = $this->searchCriteriaBuilder
             ->addFilter(SourceItemInterface::SKU, $productSku)
-            ->addFilter(SourceItemInterface::SOURCE_ID, $this->defaultSourceProvider->getId())
+            ->addFilter(SourceItemInterface::SOURCE_CODE, $this->defaultSourceProvider->getCode())
             ->create();
         $sourceItems = $this->sourceItemRepository->getList($searchCriteria)->getItems();
         if (count($sourceItems)) {
@@ -132,7 +132,7 @@ private function updateSourceItemBasedOnLegacyStockItem(Item $legacyStockItem)
         } else {
             /** @var SourceItemInterface $sourceItem */
             $sourceItem = $this->sourceItemFactory->create();
-            $sourceItem->setSourceId($this->defaultSourceProvider->getId());
+            $sourceItem->setSourceCode($this->defaultSourceProvider->getCode());
             $sourceItem->setSku($productSku);
         }
 
diff --git a/app/code/Magento/InventoryCatalog/Plugin/InventoryApi/AssignSourcesToStock/PreventAssignSourcesToDefaultStockPlugin.php b/app/code/Magento/InventoryCatalog/Plugin/InventoryApi/AssignSourcesToStock/PreventAssignSourcesToDefaultStockPlugin.php
index cc7e565ea49e..cb7945f1c22b 100644
--- a/app/code/Magento/InventoryCatalog/Plugin/InventoryApi/AssignSourcesToStock/PreventAssignSourcesToDefaultStockPlugin.php
+++ b/app/code/Magento/InventoryCatalog/Plugin/InventoryApi/AssignSourcesToStock/PreventAssignSourcesToDefaultStockPlugin.php
@@ -34,19 +34,22 @@ public function __construct(
 
     /**
      * @param AssignSourcesToStockInterface $subject
-     * @param array $sourceIds
+     * @param array $sourceCodes
      * @param int $stockId
      * @return array
      * @throws InputException
      * @SuppressWarnings(PHPMD.UnusedFormalParameter)
      */
-    public function beforeExecute(AssignSourcesToStockInterface $subject, array $sourceIds, int $stockId)
+    public function beforeExecute(AssignSourcesToStockInterface $subject, array $sourceCodes, int $stockId)
     {
-        if ($this->defaultStockProvider->getId() !== $stockId
-            || (1 == count($sourceIds) && $this->defaultSourceProvider->getId() == $sourceIds[0])) {
-            return [$sourceIds, $stockId];
+        if ($this->defaultStockProvider->getId() !== $stockId || !count($sourceCodes)) {
+            return [$sourceCodes, $stockId];
         }
 
-        throw new InputException(__('You can only assign Default Source to Default Stock'));
+        if (count($sourceCodes) > 1 || $this->defaultSourceProvider->getCode() !== (string)$sourceCodes[0]) {
+            throw new InputException(__('You can only assign Default Source to Default Stock'));
+        }
+
+        return [$sourceCodes, $stockId];
     }
 }
diff --git a/app/code/Magento/InventoryCatalog/Plugin/InventoryApi/SetDataToLegacyCatalogInventoryAtSourceItemsSavePlugin.php b/app/code/Magento/InventoryCatalog/Plugin/InventoryApi/SetDataToLegacyCatalogInventoryAtSourceItemsSavePlugin.php
index 7c70726c205b..fd20ca03ca6b 100644
--- a/app/code/Magento/InventoryCatalog/Plugin/InventoryApi/SetDataToLegacyCatalogInventoryAtSourceItemsSavePlugin.php
+++ b/app/code/Magento/InventoryCatalog/Plugin/InventoryApi/SetDataToLegacyCatalogInventoryAtSourceItemsSavePlugin.php
@@ -60,7 +60,7 @@ public function __construct(
     public function afterExecute(SourceItemsSaveInterface $subject, $result, array $sourceItems)
     {
         foreach ($sourceItems as $sourceItem) {
-            if ((int)$sourceItem->getSourceId() !== $this->defaultSourceProvider->getId()) {
+            if ($sourceItem->getSourceCode() !== $this->defaultSourceProvider->getCode()) {
                 continue;
             }
             $this->setDataToLegacyStockItem->execute(
diff --git a/app/code/Magento/InventoryCatalog/Plugin/InventoryApi/SetToZeroLegacyCatalogInventoryAtSourceItemsDeletePlugin.php b/app/code/Magento/InventoryCatalog/Plugin/InventoryApi/SetToZeroLegacyCatalogInventoryAtSourceItemsDeletePlugin.php
index 165228dc9def..b80606572818 100644
--- a/app/code/Magento/InventoryCatalog/Plugin/InventoryApi/SetToZeroLegacyCatalogInventoryAtSourceItemsDeletePlugin.php
+++ b/app/code/Magento/InventoryCatalog/Plugin/InventoryApi/SetToZeroLegacyCatalogInventoryAtSourceItemsDeletePlugin.php
@@ -61,7 +61,7 @@ public function __construct(
     public function afterExecute(SourceItemsDeleteInterface $subject, $result, array $sourceItems)
     {
         foreach ($sourceItems as $sourceItem) {
-            if ((int)$sourceItem->getSourceId() !== $this->defaultSourceProvider->getId()) {
+            if ($sourceItem->getSourceCode() !== $this->defaultSourceProvider->getCode()) {
                 continue;
             }
             $this->setDataToLegacyStockItem->execute($sourceItem->getSku(), 0, 0);
diff --git a/app/code/Magento/InventoryCatalog/Setup/Operation/AssignSourceToStock.php b/app/code/Magento/InventoryCatalog/Setup/Operation/AssignSourceToStock.php
index 7cb7e99dc5c8..d9f06f70e231 100644
--- a/app/code/Magento/InventoryCatalog/Setup/Operation/AssignSourceToStock.php
+++ b/app/code/Magento/InventoryCatalog/Setup/Operation/AssignSourceToStock.php
@@ -54,7 +54,7 @@ public function __construct(
     public function execute()
     {
         $this->assignSourcesToStock->execute(
-            [$this->defaultSourceProvider->getId()],
+            [$this->defaultSourceProvider->getCode()],
             $this->defaultStockProvider->getId()
         );
     }
diff --git a/app/code/Magento/InventoryCatalog/Setup/Operation/CreateDefaultSource.php b/app/code/Magento/InventoryCatalog/Setup/Operation/CreateDefaultSource.php
index 7cfdefd894ab..64bf4979d85c 100644
--- a/app/code/Magento/InventoryCatalog/Setup/Operation/CreateDefaultSource.php
+++ b/app/code/Magento/InventoryCatalog/Setup/Operation/CreateDefaultSource.php
@@ -64,8 +64,7 @@ public function __construct(
     public function execute()
     {
         $data = [
-            SourceInterface::SOURCE_ID => $this->defaultSourceProvider->getId(),
-            SourceInterface::CODE => 'default',
+            SourceInterface::SOURCE_CODE => $this->defaultSourceProvider->getCode(),
             SourceInterface::NAME => 'Default Source',
             SourceInterface::ENABLED => 1,
             SourceInterface::DESCRIPTION => 'Default Source',
diff --git a/app/code/Magento/InventoryCatalog/Setup/Operation/UpdateInventorySourceItem.php b/app/code/Magento/InventoryCatalog/Setup/Operation/UpdateInventorySourceItem.php
index 4a9be8da153f..8970a74b86e8 100644
--- a/app/code/Magento/InventoryCatalog/Setup/Operation/UpdateInventorySourceItem.php
+++ b/app/code/Magento/InventoryCatalog/Setup/Operation/UpdateInventorySourceItem.php
@@ -42,15 +42,12 @@ public function __construct(
     }
 
     /**
-     * Insert Stock Item to Inventory Source Item by raw MySQL query
-     *
      * @param ModuleDataSetupInterface $setup
-     *
      * @return void
      */
     public function execute(ModuleDataSetupInterface $setup)
     {
-        $defaultSourceId = $this->defaultSourceProvider->getId();
+        $defaultSourceCode = $this->defaultSourceProvider->getCode();
         $sourceItemTable = $setup->getTable(SourceItem::TABLE_NAME_SOURCE_ITEM);
         $legacyStockItemTable = $setup->getTable('cataloginventory_stock_item');
         $productTable = $setup->getTable('catalog_product_entity');
@@ -60,7 +57,7 @@ public function execute(ModuleDataSetupInterface $setup)
             ->from(
                 $legacyStockItemTable,
                 [
-                    'source_id' => new \Zend_Db_Expr($defaultSourceId),
+                    'source_code' => new \Zend_Db_Expr('\'' .$defaultSourceCode . '\''),
                     'qty',
                     'is_in_stock'
                 ]
@@ -72,7 +69,7 @@ public function execute(ModuleDataSetupInterface $setup)
             $selectForInsert,
             $sourceItemTable,
             [
-                SourceItemInterface::SOURCE_ID,
+                SourceItemInterface::SOURCE_CODE,
                 SourceItemInterface::QUANTITY,
                 SourceItemInterface::STATUS,
                 SourceItemInterface::SKU,
diff --git a/app/code/Magento/InventoryCatalog/Test/Api/GetDefaultSourceTest.php b/app/code/Magento/InventoryCatalog/Test/Api/GetDefaultSourceTest.php
index 8d5fba7ecd89..73d9d1f6a2e0 100644
--- a/app/code/Magento/InventoryCatalog/Test/Api/GetDefaultSourceTest.php
+++ b/app/code/Magento/InventoryCatalog/Test/Api/GetDefaultSourceTest.php
@@ -8,23 +8,33 @@
 namespace Magento\InventoryCatalog\Test\Api;
 
 use Magento\InventoryApi\Api\Data\SourceInterface;
+use Magento\InventoryCatalog\Api\DefaultSourceProviderInterface;
+use Magento\TestFramework\Helper\Bootstrap;
 use Magento\TestFramework\TestCase\WebapiAbstract;
 use Magento\Framework\Webapi\Rest\Request;
 
-/**
- * Class GetDefaultSourceTest
- */
 class GetDefaultSourceTest extends WebapiAbstract
 {
+    /**
+     * @var DefaultSourceProviderInterface
+     */
+    private $defaultSourceProvider;
+
+    protected function setUp()
+    {
+        parent::setUp();
+        $this->defaultSourceProvider = Bootstrap::getObjectManager()->get(DefaultSourceProviderInterface::class);
+    }
+
     /**
      * Test that default Source is present after installation
      */
     public function testGetDefaultSource()
     {
-        $defaultSourceId = 1;
+        $defaultSourceCode = $this->defaultSourceProvider->getCode();
         $serviceInfo = [
             'rest' => [
-                'resourcePath' => '/V1/inventory/source/' . $defaultSourceId,
+                'resourcePath' => '/V1/inventory/source/' . $defaultSourceCode,
                 'httpMethod' => Request::HTTP_METHOD_GET,
             ],
             'soap' => [
@@ -35,8 +45,8 @@ public function testGetDefaultSource()
         if (self::ADAPTER_REST == TESTS_WEB_API_ADAPTER) {
             $source = $this->_webApiCall($serviceInfo);
         } else {
-            $source = $this->_webApiCall($serviceInfo, ['sourceId' => $defaultSourceId]);
+            $source = $this->_webApiCall($serviceInfo, ['sourceCode' => $defaultSourceCode]);
         }
-        $this->assertEquals($defaultSourceId, $source[SourceInterface::SOURCE_ID]);
+        $this->assertEquals($defaultSourceCode, $source[SourceInterface::SOURCE_CODE]);
     }
 }
diff --git a/app/code/Magento/InventoryCatalog/Test/Api/GetDefaultStockTest.php b/app/code/Magento/InventoryCatalog/Test/Api/GetDefaultStockTest.php
index 92cf705f132a..e2c80fedf1a1 100644
--- a/app/code/Magento/InventoryCatalog/Test/Api/GetDefaultStockTest.php
+++ b/app/code/Magento/InventoryCatalog/Test/Api/GetDefaultStockTest.php
@@ -8,20 +8,30 @@
 namespace Magento\InventoryCatalog\Test\Api;
 
 use Magento\InventoryApi\Api\Data\StockInterface;
+use Magento\InventoryCatalog\Api\DefaultStockProviderInterface;
+use Magento\TestFramework\Helper\Bootstrap;
 use Magento\TestFramework\TestCase\WebapiAbstract;
 use Magento\Framework\Webapi\Rest\Request;
 
-/**
- * Class GetDefaultStockTest
- */
 class GetDefaultStockTest extends WebapiAbstract
 {
+    /**
+     * @var DefaultStockProviderInterface
+     */
+    private $defaultStockProvider;
+
+    protected function setUp()
+    {
+        parent::setUp();
+        $this->defaultStockProvider = Bootstrap::getObjectManager()->get(DefaultStockProviderInterface::class);
+    }
+
     /**
      * Test that default Stock is present after installation
      */
     public function testGetDefaultSource()
     {
-        $defaultStockId = 1;
+        $defaultStockId = $this->defaultStockProvider->getId();
         $serviceInfo = [
             'rest' => [
                 'resourcePath' => '/V1/inventory/stock/' . $defaultStockId,
diff --git a/app/code/Magento/InventoryCatalog/Test/Api/GetDefaultStockToSourceLinkTest.php b/app/code/Magento/InventoryCatalog/Test/Api/GetDefaultStockToSourceLinkTest.php
index 1df184074b6e..3a5ae2671a8b 100644
--- a/app/code/Magento/InventoryCatalog/Test/Api/GetDefaultStockToSourceLinkTest.php
+++ b/app/code/Magento/InventoryCatalog/Test/Api/GetDefaultStockToSourceLinkTest.php
@@ -8,21 +8,38 @@
 namespace Magento\InventoryCatalog\Test\Api;
 
 use Magento\InventoryApi\Api\Data\SourceInterface;
+use Magento\InventoryCatalog\Api\DefaultSourceProviderInterface;
+use Magento\InventoryCatalog\Api\DefaultStockProviderInterface;
+use Magento\TestFramework\Helper\Bootstrap;
 use Magento\TestFramework\TestCase\WebapiAbstract;
 use Magento\Framework\Webapi\Rest\Request;
 
-/**
- * Class GetDefaultStockToSourceLinkTest
- */
 class GetDefaultStockToSourceLinkTest extends WebapiAbstract
 {
+    /**
+     * @var DefaultSourceProviderInterface
+     */
+    private $defaultSourceProvider;
+
+    /**
+     * @var DefaultStockProviderInterface
+     */
+    private $defaultStockProvider;
+
+    protected function setUp()
+    {
+        parent::setUp();
+        $this->defaultSourceProvider = Bootstrap::getObjectManager()->get(DefaultSourceProviderInterface::class);
+        $this->defaultStockProvider = Bootstrap::getObjectManager()->get(DefaultStockProviderInterface::class);
+    }
+
     /**
      * Test that default Stock is present after installation
      */
     public function testGetDefaultStockToSourceLink()
     {
-        $defaultStockId = 1;
-        $defaultSourceId = 1;
+        $defaultStockId = $this->defaultStockProvider->getId();
+        $defaultSourceCode = $this->defaultSourceProvider->getCode();
         $serviceInfo = [
             'rest' => [
                 'resourcePath' => '/V1/inventory/stock/get-assigned-sources/' . $defaultStockId,
@@ -38,6 +55,6 @@ public function testGetDefaultStockToSourceLink()
         } else {
             $source = $this->_webApiCall($serviceInfo, ['stockId' => $defaultStockId]);
         }
-        $this->assertEquals([$defaultSourceId], array_column($source, SourceInterface::SOURCE_ID));
+        $this->assertEquals([$defaultSourceCode], array_column($source, SourceInterface::SOURCE_CODE));
     }
 }
diff --git a/app/code/Magento/InventoryCatalog/Test/Api/StockRepository/PreventDefaultStockDeletingTest.php b/app/code/Magento/InventoryCatalog/Test/Api/StockRepository/PreventDefaultStockDeletingTest.php
index d17b73a05bc2..e3dc317ded89 100644
--- a/app/code/Magento/InventoryCatalog/Test/Api/StockRepository/PreventDefaultStockDeletingTest.php
+++ b/app/code/Magento/InventoryCatalog/Test/Api/StockRepository/PreventDefaultStockDeletingTest.php
@@ -20,9 +20,6 @@ class PreventDefaultStockDeletingTest extends WebapiAbstract
      */
     private $defaultStockProvider;
 
-    /**
-     * {@inheritdoc}
-     */
     protected function setUp()
     {
         parent::setUp();
diff --git a/app/code/Magento/InventoryCatalog/Test/Api/StockSourceLink/AssignSourcesToStockTest.php b/app/code/Magento/InventoryCatalog/Test/Api/StockSourceLink/PreventAssignSourcesToDefaultStockTest.php
similarity index 77%
rename from app/code/Magento/InventoryCatalog/Test/Api/StockSourceLink/AssignSourcesToStockTest.php
rename to app/code/Magento/InventoryCatalog/Test/Api/StockSourceLink/PreventAssignSourcesToDefaultStockTest.php
index c3bb0ef8897a..0d818ddde169 100644
--- a/app/code/Magento/InventoryCatalog/Test/Api/StockSourceLink/AssignSourcesToStockTest.php
+++ b/app/code/Magento/InventoryCatalog/Test/Api/StockSourceLink/PreventAssignSourcesToDefaultStockTest.php
@@ -9,9 +9,12 @@
 
 use Magento\Framework\Webapi\Exception;
 use Magento\Framework\Webapi\Rest\Request;
+use Magento\InventoryCatalog\Api\DefaultSourceProviderInterface;
+use Magento\InventoryCatalog\Api\DefaultStockProviderInterface;
+use Magento\TestFramework\Helper\Bootstrap;
 use Magento\TestFramework\TestCase\WebapiAbstract;
 
-class AssignSourcesToStockTest extends WebapiAbstract
+class PreventAssignSourcesToDefaultStockTest extends WebapiAbstract
 {
     /**#@+
      * Service constants
@@ -23,14 +26,14 @@ class AssignSourcesToStockTest extends WebapiAbstract
     /**
      * @magentoApiDataFixture ../../../../app/code/Magento/InventoryApi/Test/_files/sources.php
      * @magentoApiDataFixture ../../../../app/code/Magento/InventoryApi/Test/_files/stock.php
-     * @param array $sourceIds
+     * @param array $sourceCodes
      * @param int $stockId
      * @param array $expectedErrorData
      * @throws \Exception
      * @dataProvider dataProviderWrongParameters
      */
     public function testAssignSourcesToStockWithWrongParameters(
-        array $sourceIds,
+        array $sourceCodes,
         int $stockId,
         array $expectedErrorData
     ) {
@@ -46,8 +49,8 @@ public function testAssignSourcesToStockWithWrongParameters(
         ];
         try {
             (TESTS_WEB_API_ADAPTER == self::ADAPTER_REST)
-                ? $this->_webApiCall($serviceInfo, ['sourceIds' => $sourceIds])
-                : $this->_webApiCall($serviceInfo, ['sourceIds' => $sourceIds, 'stockId' => $stockId]);
+                ? $this->_webApiCall($serviceInfo, ['sourceCodes' => $sourceCodes])
+                : $this->_webApiCall($serviceInfo, ['sourceCodes' => $sourceCodes, 'stockId' => $stockId]);
             $this->fail('Expected throwing exception');
         } catch (\Exception $e) {
             if (TESTS_WEB_API_ADAPTER == self::ADAPTER_REST) {
@@ -72,18 +75,21 @@ public function testAssignSourcesToStockWithWrongParameters(
      */
     public function dataProviderWrongParameters(): array
     {
+        $defaultSourceProvider = Bootstrap::getObjectManager()->get(DefaultSourceProviderInterface::class);
+        $defaultStockProvider = Bootstrap::getObjectManager()->get(DefaultStockProviderInterface::class);
+
         return [
             'multiple_sources_assigned_to_default_stock' => [
-                [1, 20],
-                1,
+                [$defaultSourceProvider->getCode(), 'eu-2'],
+                $defaultStockProvider->getId(),
                 [
                     'rest_message' => 'You can only assign Default Source to Default Stock',
                     'soap_message' => 'You can only assign Default Source to Default Stock',
                 ],
             ],
             'not_default_source_assigned_to_default_stock' => [
-                [10],
-                1,
+                ['eu-1'],
+                $defaultStockProvider->getId(),
                 [
                     'rest_message' => 'You can only assign Default Source to Default Stock',
                     'soap_message' => 'You can only assign Default Source to Default Stock',
diff --git a/app/code/Magento/InventoryCatalog/Test/Integration/SetDataToLegacyStockItemAtSourceItemsSaveTest.php b/app/code/Magento/InventoryCatalog/Test/Integration/SetDataToLegacyStockItemAtSourceItemsSaveTest.php
index 40db7a4aeb7d..c32e7370d1f1 100644
--- a/app/code/Magento/InventoryCatalog/Test/Integration/SetDataToLegacyStockItemAtSourceItemsSaveTest.php
+++ b/app/code/Magento/InventoryCatalog/Test/Integration/SetDataToLegacyStockItemAtSourceItemsSaveTest.php
@@ -96,7 +96,7 @@ public function testSetData()
 
         $searchCriteria = $this->searchCriteriaBuilder
             ->addFilter(SourceItemInterface::SKU, $productSku)
-            ->addFilter(SourceItemInterface::SOURCE_ID, $this->defaultSourceProvider->getId())
+            ->addFilter(SourceItemInterface::SOURCE_CODE, $this->defaultSourceProvider->getCode())
             ->create();
         $sourceItems = $this->sourceItemRepository->getList($searchCriteria)->getItems();
         self::assertCount(1, $sourceItems);
diff --git a/app/code/Magento/InventoryCatalog/Test/Integration/SetDataToLegacyStockStatusAtSourceItemsSaveTest.php b/app/code/Magento/InventoryCatalog/Test/Integration/SetDataToLegacyStockStatusAtSourceItemsSaveTest.php
index d8457df5ea81..224f2f88eb49 100644
--- a/app/code/Magento/InventoryCatalog/Test/Integration/SetDataToLegacyStockStatusAtSourceItemsSaveTest.php
+++ b/app/code/Magento/InventoryCatalog/Test/Integration/SetDataToLegacyStockStatusAtSourceItemsSaveTest.php
@@ -97,7 +97,7 @@ public function testSetData()
 
         $searchCriteria = $this->searchCriteriaBuilder
             ->addFilter(SourceItemInterface::SKU, $productSku)
-            ->addFilter(SourceItemInterface::SOURCE_ID, $this->defaultSourceProvider->getId())
+            ->addFilter(SourceItemInterface::SOURCE_CODE, $this->defaultSourceProvider->getCode())
             ->create();
         $sourceItems = $this->sourceItemRepository->getList($searchCriteria)->getItems();
         self::assertCount(1, $sourceItems);
diff --git a/app/code/Magento/InventoryCatalog/Test/Integration/SetOutOfStockToLegacyStockStatusAtSourceItemsDeleteTest.php b/app/code/Magento/InventoryCatalog/Test/Integration/SetOutOfStockToLegacyStockStatusAtSourceItemsDeleteTest.php
index 900494f0daaf..906c84bd178d 100644
--- a/app/code/Magento/InventoryCatalog/Test/Integration/SetOutOfStockToLegacyStockStatusAtSourceItemsDeleteTest.php
+++ b/app/code/Magento/InventoryCatalog/Test/Integration/SetOutOfStockToLegacyStockStatusAtSourceItemsDeleteTest.php
@@ -97,7 +97,7 @@ public function testSetOutOfStock()
 
         $searchCriteria = $this->searchCriteriaBuilder
             ->addFilter(SourceItemInterface::SKU, $productSku)
-            ->addFilter(SourceItemInterface::SOURCE_ID, $this->defaultSourceProvider->getId())
+            ->addFilter(SourceItemInterface::SOURCE_CODE, $this->defaultSourceProvider->getCode())
             ->create();
         $sourceItems = $this->sourceItemRepository->getList($searchCriteria)->getItems();
         self::assertCount(1, $sourceItems);
diff --git a/app/code/Magento/InventoryCatalog/Test/Integration/SetToZeroLegacyStockItemAtSourceItemsDeleteTest.php b/app/code/Magento/InventoryCatalog/Test/Integration/SetToZeroLegacyStockItemAtSourceItemsDeleteTest.php
index f3044e2731cd..27c97cad3e6e 100644
--- a/app/code/Magento/InventoryCatalog/Test/Integration/SetToZeroLegacyStockItemAtSourceItemsDeleteTest.php
+++ b/app/code/Magento/InventoryCatalog/Test/Integration/SetToZeroLegacyStockItemAtSourceItemsDeleteTest.php
@@ -96,7 +96,7 @@ public function testSetToZero()
 
         $searchCriteria = $this->searchCriteriaBuilder
             ->addFilter(SourceItemInterface::SKU, $productSku)
-            ->addFilter(SourceItemInterface::SOURCE_ID, $this->defaultSourceProvider->getId())
+            ->addFilter(SourceItemInterface::SOURCE_CODE, $this->defaultSourceProvider->getCode())
             ->create();
         $sourceItems = $this->sourceItemRepository->getList($searchCriteria)->getItems();
         self::assertCount(1, $sourceItems);
diff --git a/app/code/Magento/InventoryCatalog/Test/_files/source_items_on_default_source.php b/app/code/Magento/InventoryCatalog/Test/_files/source_items_on_default_source.php
index e3b45e313baa..c7919c4125b8 100644
--- a/app/code/Magento/InventoryCatalog/Test/_files/source_items_on_default_source.php
+++ b/app/code/Magento/InventoryCatalog/Test/_files/source_items_on_default_source.php
@@ -28,19 +28,19 @@
  */
 $sourcesItemsData = [
     [
-        SourceItemInterface::SOURCE_ID => $defaultSourceProvider->getId(),
+        SourceItemInterface::SOURCE_CODE => $defaultSourceProvider->getCode(),
         SourceItemInterface::SKU => 'SKU-1',
         SourceItemInterface::QUANTITY => 5.5,
         SourceItemInterface::STATUS => SourceItemInterface::STATUS_IN_STOCK,
     ],
     [
-        SourceItemInterface::SOURCE_ID => $defaultSourceProvider->getId(),
+        SourceItemInterface::SOURCE_CODE => $defaultSourceProvider->getCode(),
         SourceItemInterface::SKU => 'SKU-2',
         SourceItemInterface::QUANTITY => 5,
         SourceItemInterface::STATUS => SourceItemInterface::STATUS_IN_STOCK,
     ],
     [
-        SourceItemInterface::SOURCE_ID => $defaultSourceProvider->getId(),
+        SourceItemInterface::SOURCE_CODE => $defaultSourceProvider->getCode(),
         SourceItemInterface::SKU => 'SKU-3',
         SourceItemInterface::QUANTITY => 6,
         SourceItemInterface::STATUS => SourceItemInterface::STATUS_OUT_OF_STOCK,
diff --git a/app/code/Magento/InventoryCatalog/Ui/DataProvider/Product/Form/Modifier/Sources.php b/app/code/Magento/InventoryCatalog/Ui/DataProvider/Product/Form/Modifier/Sources.php
index d6d61534cf7b..d8b2ed60f37e 100644
--- a/app/code/Magento/InventoryCatalog/Ui/DataProvider/Product/Form/Modifier/Sources.php
+++ b/app/code/Magento/InventoryCatalog/Ui/DataProvider/Product/Form/Modifier/Sources.php
@@ -75,14 +75,14 @@ private function getSourceItemsData(): array
         $collection->addFilter(SourceItemInterface::SKU, $product->getSku());
         $collection->join(
             ['s' => $this->resourceConnection->getTableName(SourceResourceModel::TABLE_NAME_SOURCE)],
-            sprintf('s.%s = main_table.%s', SourceInterface::SOURCE_ID, SourceItemInterface::SOURCE_ID),
+            sprintf('s.%s = main_table.%s', SourceInterface::SOURCE_CODE, SourceItemInterface::SOURCE_CODE),
             ['source_name' => SourceInterface::NAME]
         );
 
         $sourceItemsData = [];
         foreach ($collection->getData() as $row) {
             $sourceItemsData[] = [
-                SourceItemInterface::SOURCE_ID => $row[SourceItemInterface::SOURCE_ID],
+                SourceItemInterface::SOURCE_CODE => $row[SourceItemInterface::SOURCE_CODE],
                 SourceItemInterface::QUANTITY => $row[SourceItemInterface::QUANTITY],
                 SourceItemInterface::STATUS => $row[SourceItemInterface::STATUS],
                 SourceInterface::NAME => $row['source_name'],
diff --git a/app/code/Magento/InventoryCatalog/view/adminhtml/ui_component/product_form.xml b/app/code/Magento/InventoryCatalog/view/adminhtml/ui_component/product_form.xml
index 30b27eb2ebfa..5d47d1a64faf 100644
--- a/app/code/Magento/InventoryCatalog/view/adminhtml/ui_component/product_form.xml
+++ b/app/code/Magento/InventoryCatalog/view/adminhtml/ui_component/product_form.xml
@@ -45,11 +45,11 @@
                 <item name="config" xsi:type="array">
                     <item name="dataProvider" xsi:type="string">data.sources.assign_sources_grid</item>
                     <item name="map" xsi:type="array">
-                        <item name="source_id" xsi:type="string">source_id</item>
+                        <item name="source_code" xsi:type="string">source_code</item>
                         <item name="name" xsi:type="string">name</item>
                         <item name="qty" xsi:type="string">qty</item>
                     </item>
-                    <item name="identificationDRProperty" xsi:type="string">source_id</item>
+                    <item name="identificationDRProperty" xsi:type="string">source_code</item>
                 </item>
             </argument>
             <settings>
@@ -57,7 +57,7 @@
                 <defaultRecord>false</defaultRecord>
                 <addButton>false</addButton>
                 <recordTemplate>record</recordTemplate>
-                <identificationProperty>source_id</identificationProperty>
+                <identificationProperty>source_code</identificationProperty>
                 <links>
                     <link name="insertData">${ $.provider }:${ $.dataProvider }</link>
                 </links>
@@ -74,11 +74,11 @@
                         <item name="dataScope" xsi:type="string"/>
                     </item>
                 </argument>
-                <field name="source_id" formElement="input" sortOrder="10">
+                <field name="source_code" formElement="input" sortOrder="10">
                     <settings>
                         <elementTmpl>ui/dynamic-rows/cells/text</elementTmpl>
                         <dataType>text</dataType>
-                        <dataScope>source_id</dataScope>
+                        <dataScope>source_code</dataScope>
                         <label translate="true">ID</label>
                     </settings>
                 </field>
diff --git a/app/code/Magento/InventoryConfiguration/Model/ResourceModel/SourceItemConfiguration/Delete.php b/app/code/Magento/InventoryConfiguration/Model/ResourceModel/SourceItemConfiguration/Delete.php
index 85ec1d86eba7..cc5f991547d3 100644
--- a/app/code/Magento/InventoryConfiguration/Model/ResourceModel/SourceItemConfiguration/Delete.php
+++ b/app/code/Magento/InventoryConfiguration/Model/ResourceModel/SourceItemConfiguration/Delete.php
@@ -31,18 +31,18 @@ public function __construct(
     }
 
     /**
-     * @param int $sourceId
+     * @param string $sourceCode
      * @param string $sku
      * @return void
      */
-    public function execute(int $sourceId, string $sku)
+    public function execute(string $sourceCode, string $sku)
     {
         $connection = $this->resourceConnection->getConnection();
         $sourceItemConfigurationTable = $this->resourceConnection
             ->getTableName(CreateSourceConfigurationTable::TABLE_NAME_SOURCE_ITEM_CONFIGURATION);
 
         $connection->delete($sourceItemConfigurationTable, [
-            SourceItemConfigurationInterface::SOURCE_ID . ' = ?' => $sourceId,
+            SourceItemConfigurationInterface::SOURCE_CODE . ' = ?' => $sourceCode,
             SourceItemConfigurationInterface::SKU . ' = ?' => $sku,
         ]);
     }
diff --git a/app/code/Magento/InventoryConfiguration/Model/ResourceModel/SourceItemConfiguration/GetData.php b/app/code/Magento/InventoryConfiguration/Model/ResourceModel/SourceItemConfiguration/GetData.php
index 7067ea0deebc..cc81eae31b78 100644
--- a/app/code/Magento/InventoryConfiguration/Model/ResourceModel/SourceItemConfiguration/GetData.php
+++ b/app/code/Magento/InventoryConfiguration/Model/ResourceModel/SourceItemConfiguration/GetData.php
@@ -30,11 +30,11 @@ public function __construct(ResourceConnection $resourceConnection)
     }
 
     /**
-     * @param int $sourceId
+     * @param string $sourceCode
      * @param string $sku
      * @return array|null
      */
-    public function execute(int $sourceId, string $sku)
+    public function execute(string $sourceCode, string $sku)
     {
         $connection = $this->resourceConnection->getConnection();
         $sourceItemConfigurationTable = $this->resourceConnection
@@ -42,7 +42,7 @@ public function execute(int $sourceId, string $sku)
 
         $select = $connection->select()
             ->from($sourceItemConfigurationTable)
-            ->where(SourceItemConfigurationInterface::SOURCE_ID . ' = ?', $sourceId)
+            ->where(SourceItemConfigurationInterface::SOURCE_CODE . ' = ?', $sourceCode)
             ->where(SourceItemConfigurationInterface::SKU . ' = ?', $sku);
 
         $row = $connection->fetchRow($select);
diff --git a/app/code/Magento/InventoryConfiguration/Model/ResourceModel/SourceItemConfiguration/SaveMultiple.php b/app/code/Magento/InventoryConfiguration/Model/ResourceModel/SourceItemConfiguration/SaveMultiple.php
index 9852ac57e3c1..734c757a9e1f 100644
--- a/app/code/Magento/InventoryConfiguration/Model/ResourceModel/SourceItemConfiguration/SaveMultiple.php
+++ b/app/code/Magento/InventoryConfiguration/Model/ResourceModel/SourceItemConfiguration/SaveMultiple.php
@@ -45,7 +45,7 @@ public function execute(array $sourceItemConfigurations)
             ->getTableName(CreateSourceConfigurationTable::TABLE_NAME_SOURCE_ITEM_CONFIGURATION);
 
         $columnsSql = $this->buildColumnsSqlPart([
-            SourceItemConfigurationInterface::SOURCE_ID,
+            SourceItemConfigurationInterface::SOURCE_CODE,
             SourceItemConfigurationInterface::SKU,
             SourceItemConfigurationInterface::INVENTORY_NOTIFY_QTY
         ]);
@@ -97,7 +97,7 @@ private function getSqlBindData(array $sourceItemConfigurations): array
         $bind = [];
         foreach ($sourceItemConfigurations as $sourceItemConfiguration) {
             $bind = array_merge($bind, [
-                $sourceItemConfiguration->getSourceId(),
+                $sourceItemConfiguration->getSourceCode(),
                 $sourceItemConfiguration->getSku(),
                 $sourceItemConfiguration->getNotifyStockQty()
             ]);
diff --git a/app/code/Magento/InventoryConfiguration/Model/SourceItemConfiguration.php b/app/code/Magento/InventoryConfiguration/Model/SourceItemConfiguration.php
index df97d1ea365a..6986d557aed9 100644
--- a/app/code/Magento/InventoryConfiguration/Model/SourceItemConfiguration.php
+++ b/app/code/Magento/InventoryConfiguration/Model/SourceItemConfiguration.php
@@ -19,17 +19,17 @@ class SourceItemConfiguration extends AbstractExtensibleModel implements SourceI
     /**
      * @inheritdoc
      */
-    public function getSourceId()
+    public function getSourceCode()
     {
-        return $this->getData(self::SOURCE_ID);
+        return $this->getData(self::SOURCE_CODE);
     }
 
     /**
      * @inheritdoc
      */
-    public function setSourceId(int $sourceId)
+    public function setSourceCode(string $sourceCode)
     {
-        $this->setData(self::SOURCE_ID, $sourceId);
+        $this->setData(self::SOURCE_CODE, $sourceCode);
     }
 
     /**
diff --git a/app/code/Magento/InventoryConfiguration/Model/SourceItemConfiguration/Command/Delete.php b/app/code/Magento/InventoryConfiguration/Model/SourceItemConfiguration/Command/Delete.php
index 93c43a880653..1dc92a8363c7 100644
--- a/app/code/Magento/InventoryConfiguration/Model/SourceItemConfiguration/Command/Delete.php
+++ b/app/code/Magento/InventoryConfiguration/Model/SourceItemConfiguration/Command/Delete.php
@@ -42,10 +42,10 @@ public function __construct(
     /**
      * @inheritdoc
      */
-    public function execute(int $sourceId, string $sku)
+    public function execute(string $sourceCode, string $sku)
     {
         try {
-            $this->deleteResourceModel->execute($sourceId, $sku);
+            $this->deleteResourceModel->execute($sourceCode, $sku);
         } catch (\Exception $e) {
             $this->logger->error($e->getMessage());
             throw new CouldNotDeleteException(__('Could not delete SourceItem Configuration.'), $e);
diff --git a/app/code/Magento/InventoryConfiguration/Model/SourceItemConfiguration/Command/Get.php b/app/code/Magento/InventoryConfiguration/Model/SourceItemConfiguration/Command/Get.php
index 534a59332d55..0de225311254 100644
--- a/app/code/Magento/InventoryConfiguration/Model/SourceItemConfiguration/Command/Get.php
+++ b/app/code/Magento/InventoryConfiguration/Model/SourceItemConfiguration/Command/Get.php
@@ -70,14 +70,14 @@ public function __construct(
     /**
      * @inheritdoc
      */
-    public function execute(int $sourceId, string $sku): SourceItemConfigurationInterface
+    public function execute(string $sourceCode, string $sku): SourceItemConfigurationInterface
     {
-        if (empty($sourceId) || empty($sku)) {
+        if (empty($sourceCode) || empty($sku)) {
             throw new InputException(__('Wrong input data'));
         }
 
         try {
-            return $this->getConfiguration($sourceId, $sku);
+            return $this->getConfiguration($sourceCode, $sku);
         } catch (\Exception $e) {
             $this->logger->error($e->getMessage());
             throw new LocalizedException(__('Could not load Source Item Configuration.'), $e);
@@ -85,16 +85,16 @@ public function execute(int $sourceId, string $sku): SourceItemConfigurationInte
     }
 
     /**
-     * @param int $sourceId
+     * @param string $sourceCode
      * @param string $sku
      * @return SourceItemConfigurationInterface
      */
-    private function getConfiguration(int $sourceId, string $sku): SourceItemConfigurationInterface
+    private function getConfiguration(string $sourceCode, string $sku): SourceItemConfigurationInterface
     {
-        $sourceItemConfigurationData = $this->getDataResourceModel->execute($sourceId, $sku);
+        $sourceItemConfigurationData = $this->getDataResourceModel->execute($sourceCode, $sku);
 
         if (null === $sourceItemConfigurationData) {
-            $sourceItemConfigurationData = $this->getDefaultValues->execute($sourceId, $sku);
+            $sourceItemConfigurationData = $this->getDefaultValues->execute($sourceCode, $sku);
         }
 
         /** @var SourceItemConfigurationInterface $sourceItem */
diff --git a/app/code/Magento/InventoryConfiguration/Model/SourceItemConfiguration/Command/GetDefaultValues.php b/app/code/Magento/InventoryConfiguration/Model/SourceItemConfiguration/Command/GetDefaultValues.php
index e85ef95b7101..02d5d71c7516 100644
--- a/app/code/Magento/InventoryConfiguration/Model/SourceItemConfiguration/Command/GetDefaultValues.php
+++ b/app/code/Magento/InventoryConfiguration/Model/SourceItemConfiguration/Command/GetDefaultValues.php
@@ -35,16 +35,16 @@ public function __construct(
     }
 
     /**
-     * @param int $sourceId
+     * @param string $sourceCode
      * @param string $sku
      * @return array
      */
-    public function execute(int $sourceId, string $sku) : array
+    public function execute(string $sourceCode, string $sku) : array
     {
         $inventoryNotifyQty = (float)$this->scopeConfig->getValue(self::XML_PATH_NOTIFY_STOCK_QTY);
 
         $defaultConfiguration = [
-            SourceItemConfigurationInterface::SOURCE_ID => $sourceId,
+            SourceItemConfigurationInterface::SOURCE_CODE => $sourceCode,
             SourceItemConfigurationInterface::SKU => $sku,
             SourceItemConfigurationInterface::INVENTORY_NOTIFY_QTY => $inventoryNotifyQty,
         ];
diff --git a/app/code/Magento/InventoryConfiguration/Observer/SourceItemsConfigurationProcessor.php b/app/code/Magento/InventoryConfiguration/Observer/SourceItemsConfigurationProcessor.php
index 648477e6e6b2..4b0e1e2b5334 100644
--- a/app/code/Magento/InventoryConfiguration/Observer/SourceItemsConfigurationProcessor.php
+++ b/app/code/Magento/InventoryConfiguration/Observer/SourceItemsConfigurationProcessor.php
@@ -73,9 +73,9 @@ public function process($sku, array $sourceItemsData)
         foreach ($sourceItemsData as $sourceItemData) {
             $this->validateSourceItemData($sourceItemData);
 
-            $sourceId = $sourceItemData[SourceItemInterface::SOURCE_ID];
-            if (isset($sourceItemsForDelete[$sourceId])) {
-                $sourceItem = $sourceItemsForDelete[$sourceId];
+            $sourceCode = $sourceItemData[SourceItemInterface::SOURCE_CODE];
+            if (isset($sourceItemsForDelete[$sourceCode])) {
+                $sourceItem = $sourceItemsForDelete[$sourceCode];
             } else {
                 /** @var SourceItemInterface $sourceItem */
                 $sourceItem = $this->sourceItemConfigurationFactory->create();
@@ -89,7 +89,7 @@ public function process($sku, array $sourceItemsData)
             );
 
             $sourceItemsForSave[] = $sourceItem;
-            unset($sourceItemsForDelete[$sourceId]);
+            unset($sourceItemsForDelete[$sourceCode]);
         }
         if ($sourceItemsForSave) {
             $this->sourceItemConfigurationSave->execute($sourceItemsForSave);
@@ -112,8 +112,8 @@ private function getCurrentSourceItemsMap(string $sku, array $sourceItemsData):
 
         /** @var \Magento\Inventory\Model\SourceItem $sourceItem */
         foreach ($sourceItemsData as $sourceItem) {
-            $sourceId = $sourceItem[SourceItemInterface::SOURCE_ID];
-            $sourceItemConfig = $this->getSourceItemConfiguration->execute((int)$sourceId, $sku);
+            $sourceCode = $sourceItem[SourceItemInterface::SOURCE_CODE];
+            $sourceItemConfig = $this->getSourceItemConfiguration->execute((string)$sourceCode, $sku);
 
             if (null !== $sourceItemConfig) {
                 $sourceItems[] = $sourceItemConfig;
@@ -123,7 +123,7 @@ private function getCurrentSourceItemsMap(string $sku, array $sourceItemsData):
         $sourceItemMap = [];
         if ($sourceItems) {
             foreach ($sourceItems as $sourceItem) {
-                $sourceItemMap[(int)$sourceItem[SourceItemInterface::SOURCE_ID]] = $sourceItem;
+                $sourceItemMap[(string)$sourceItem[SourceItemInterface::SOURCE_CODE]] = $sourceItem;
             }
         }
         return $sourceItemMap;
@@ -136,7 +136,7 @@ private function getCurrentSourceItemsMap(string $sku, array $sourceItemsData):
      */
     private function validateSourceItemData(array $sourceItemData)
     {
-        if (!isset($sourceItemData[SourceItemInterface::SOURCE_ID])) {
+        if (!isset($sourceItemData[SourceItemInterface::SOURCE_CODE])) {
             throw new InputException(__('Wrong Product to Source relation parameters given.'));
         }
     }
@@ -150,7 +150,7 @@ private function deleteSourceItemsConfiguration(array $sourceItemsConfigurations
         /** @var SourceItemInterface $sourceItemConfiguration */
         foreach ($sourceItemsConfigurations as $sourceItemConfiguration) {
             $this->sourceItemConfigurationDelete->execute(
-                $sourceItemConfiguration->getSourceId(),
+                $sourceItemConfiguration->getSourceCode(),
                 $sourceItemConfiguration->getSku()
             );
         }
diff --git a/app/code/Magento/InventoryConfiguration/Setup/Operation/CreateSourceConfigurationTable.php b/app/code/Magento/InventoryConfiguration/Setup/Operation/CreateSourceConfigurationTable.php
index e9fb15dbc3d4..57241dfd9675 100644
--- a/app/code/Magento/InventoryConfiguration/Setup/Operation/CreateSourceConfigurationTable.php
+++ b/app/code/Magento/InventoryConfiguration/Setup/Operation/CreateSourceConfigurationTable.php
@@ -14,7 +14,6 @@
 use Magento\Inventory\Model\ResourceModel\SourceItem;
 use Magento\InventoryApi\Api\Data\SourceItemInterface;
 use Magento\InventoryConfigurationApi\Api\Data\SourceItemConfigurationInterface;
-use Magento\InventoryApi\Api\Data\SourceInterface;
 
 class CreateSourceConfigurationTable
 {
@@ -50,14 +49,13 @@ public function execute(SchemaSetupInterface $setup)
     private function addBaseFields(Table $sourceItemConfigurationTable): Table
     {
         return $sourceItemConfigurationTable->addColumn(
-            SourceItemConfigurationInterface::SOURCE_ID,
-            Table::TYPE_INTEGER,
-            null,
+            SourceItemConfigurationInterface::SOURCE_CODE,
+            Table::TYPE_TEXT,
+            255,
             [
-                Table::OPTION_UNSIGNED => true,
                 Table::OPTION_NULLABLE => false,
             ],
-            'Source ID'
+            'Source Code'
         )->addColumn(
             SourceItemInterface::SKU,
             Table::TYPE_TEXT,
@@ -80,7 +78,7 @@ private function addBaseFields(Table $sourceItemConfigurationTable): Table
             'Notify Quantity'
         )->addIndex(
             'idx_primary',
-            [SourceItemConfigurationInterface::SOURCE_ID, SourceItemInterface::SKU],
+            [SourceItemConfigurationInterface::SOURCE_CODE, SourceItemInterface::SKU],
             ['type' => AdapterInterface::INDEX_TYPE_PRIMARY]
         );
     }
@@ -101,13 +99,13 @@ private function addForeignKey(
         return $sourceItemConfigurationTable->addForeignKey(
             $setup->getFkName(
                 $sourceItemConfigurationTable->getName(),
-                SourceItemConfigurationInterface::SOURCE_ID,
+                SourceItemConfigurationInterface::SOURCE_CODE,
                 $sourceItemTable,
-                SourceInterface::SOURCE_ID
+                SourceItemInterface::SOURCE_CODE
             ),
-            SourceItemConfigurationInterface::SOURCE_ID,
+            SourceItemConfigurationInterface::SOURCE_CODE,
             $sourceItemTable,
-            SourceInterface::SOURCE_ID,
+            SourceItemInterface::SOURCE_CODE,
             AdapterInterface::FK_ACTION_CASCADE
         );
     }
diff --git a/app/code/Magento/InventoryConfiguration/Ui/DataProvider/Product/Form/Modifier/SourceItemConfiguration.php b/app/code/Magento/InventoryConfiguration/Ui/DataProvider/Product/Form/Modifier/SourceItemConfiguration.php
index 1bd4b78b30b0..bf9de2b99f8e 100644
--- a/app/code/Magento/InventoryConfiguration/Ui/DataProvider/Product/Form/Modifier/SourceItemConfiguration.php
+++ b/app/code/Magento/InventoryConfiguration/Ui/DataProvider/Product/Form/Modifier/SourceItemConfiguration.php
@@ -65,18 +65,19 @@ private function getSourceItemsConfigurationData(array $assignedSources, Product
     {
         foreach ($assignedSources as &$source) {
             $sourceConfiguration = $this->getSourceItemConfiguration->execute(
-                (int)$source[SourceInterface::SOURCE_ID],
+                (string)$source[SourceInterface::SOURCE_CODE],
                 $product->getSku()
             );
 
             $source[SourceItemConfigurationInterface::INVENTORY_NOTIFY_QTY] =
                 $sourceConfiguration[SourceItemConfigurationInterface::INVENTORY_NOTIFY_QTY];
         }
+        unset($source);
         return $assignedSources;
     }
 
     /**
-     * {@inheritdoc}
+     * @inheritdoc
      */
     public function modifyMeta(array $meta)
     {
diff --git a/app/code/Magento/InventoryConfiguration/view/adminhtml/ui_component/product_form.xml b/app/code/Magento/InventoryConfiguration/view/adminhtml/ui_component/product_form.xml
index 513d3c89d4cc..3bbe8298ea41 100644
--- a/app/code/Magento/InventoryConfiguration/view/adminhtml/ui_component/product_form.xml
+++ b/app/code/Magento/InventoryConfiguration/view/adminhtml/ui_component/product_form.xml
@@ -13,7 +13,7 @@
                     <item name="map" xsi:type="array">
                         <item name="notify_stock_qty" xsi:type="string">notify_stock_qty</item>
                     </item>
-                    <item name="identificationDRProperty" xsi:type="string">source_id</item>
+                    <item name="identificationDRProperty" xsi:type="string">source_code</item>
                 </item>
             </argument>
             <container name="record" component="Magento_Ui/js/dynamic-rows/record">
diff --git a/app/code/Magento/InventoryConfigurationApi/Api/Data/SourceItemConfigurationInterface.php b/app/code/Magento/InventoryConfigurationApi/Api/Data/SourceItemConfigurationInterface.php
index a2983729e249..ac024aa787f4 100644
--- a/app/code/Magento/InventoryConfigurationApi/Api/Data/SourceItemConfigurationInterface.php
+++ b/app/code/Magento/InventoryConfigurationApi/Api/Data/SourceItemConfigurationInterface.php
@@ -21,24 +21,24 @@ interface SourceItemConfigurationInterface extends ExtensibleDataInterface
     /**
      * Constant for fields in data array
      */
-    const SOURCE_ID = 'source_id';
+    const SOURCE_CODE = 'source_code';
     const SKU = 'sku';
     const INVENTORY_NOTIFY_QTY = 'notify_stock_qty';
 
     /**
-     * Get source id
+     * Get source code
      *
-     * @return int|null
+     * @return string|null
      */
-    public function getSourceId();
+    public function getSourceCode();
 
     /**
-     * Set source id
+     * Set source code
      *
-     * @param int $sourceId
+     * @param string $sourceCode
      * @return void
      */
-    public function setSourceId(int $sourceId);
+    public function setSourceCode(string $sourceCode);
 
     /**
      * Get notify stock qty
diff --git a/app/code/Magento/InventoryConfigurationApi/Api/DeleteSourceItemConfigurationInterface.php b/app/code/Magento/InventoryConfigurationApi/Api/DeleteSourceItemConfigurationInterface.php
index 2f1fc53140ad..1edcdadc2448 100644
--- a/app/code/Magento/InventoryConfigurationApi/Api/DeleteSourceItemConfigurationInterface.php
+++ b/app/code/Magento/InventoryConfigurationApi/Api/DeleteSourceItemConfigurationInterface.php
@@ -15,9 +15,9 @@
 interface DeleteSourceItemConfigurationInterface
 {
     /**
-     * @param int $sourceId
+     * @param string $sourceCode
      * @param string $sku
      * @return void
      */
-    public function execute(int $sourceId, string $sku);
+    public function execute(string $sourceCode, string $sku);
 }
diff --git a/app/code/Magento/InventoryConfigurationApi/Api/GetSourceItemConfigurationInterface.php b/app/code/Magento/InventoryConfigurationApi/Api/GetSourceItemConfigurationInterface.php
index 44da3d8e80a1..2863ab4f3dd6 100644
--- a/app/code/Magento/InventoryConfigurationApi/Api/GetSourceItemConfigurationInterface.php
+++ b/app/code/Magento/InventoryConfigurationApi/Api/GetSourceItemConfigurationInterface.php
@@ -22,10 +22,10 @@ interface GetSourceItemConfigurationInterface
     /**
      * Get the source item configuration
      *
-     * @param int $sourceId
+     * @param string $sourceCode
      * @param string $sku
      * @return \Magento\InventoryConfigurationApi\Api\Data\SourceItemConfigurationInterface
      * @throws \Magento\Framework\Exception\LocalizedException
      */
-    public function execute(int $sourceId, string $sku): SourceItemConfigurationInterface;
+    public function execute(string $sourceCode, string $sku): SourceItemConfigurationInterface;
 }
diff --git a/app/code/Magento/InventoryConfigurationApi/Test/Api/DeleteSourceItemConfigurationTest.php b/app/code/Magento/InventoryConfigurationApi/Test/Api/DeleteSourceItemConfigurationTest.php
index 9ad27bac8815..7d3f28085160 100644
--- a/app/code/Magento/InventoryConfigurationApi/Test/Api/DeleteSourceItemConfigurationTest.php
+++ b/app/code/Magento/InventoryConfigurationApi/Test/Api/DeleteSourceItemConfigurationTest.php
@@ -24,13 +24,13 @@ class DeleteSourceItemConfigurationTest extends WebapiAbstract
      */
     public function testDeleteSourceItemConfiguration()
     {
-        $sourceId = 10;
+        $sourceCode = 'eu-1';
         $sku = 'SKU-1';
 
         $serviceInfo = [
             'rest' => [
                 'resourcePath' => self::RESOURCE_PATH . '?'
-                    . http_build_query(['sourceId' => $sourceId, 'sku' => $sku]),
+                    . http_build_query(['sourceCode' => $sourceCode, 'sku' => $sku]),
                 'httpMethod' => Request::HTTP_METHOD_DELETE,
             ],
             'soap' => [
@@ -41,9 +41,9 @@ public function testDeleteSourceItemConfiguration()
 
         (TESTS_WEB_API_ADAPTER == self::ADAPTER_REST)
             ? $this->_webApiCall($serviceInfo)
-            : $this->_webApiCall($serviceInfo, ['sourceId' => $sourceId, 'sku' => $sku]);
+            : $this->_webApiCall($serviceInfo, ['sourceCode' => $sourceCode, 'sku' => $sku]);
 
-        $sourceItemConfiguration = $this->getSourceItemConfiguration($sourceId, $sku);
+        $sourceItemConfiguration = $this->getSourceItemConfiguration($sourceCode, $sku);
         $defaultNotifyQtyValue = 1;
         self::assertEquals(
             $defaultNotifyQtyValue,
@@ -52,15 +52,15 @@ public function testDeleteSourceItemConfiguration()
     }
 
     /**
-     * @param int $sourceId
+     * @param string $sourceCode
      * @param string $sku
      * @return array
      */
-    private function getSourceItemConfiguration(int $sourceId, string $sku)
+    private function getSourceItemConfiguration(string $sourceCode, string $sku)
     {
         $serviceInfo = [
             'rest' => [
-                'resourcePath' => self::RESOURCE_PATH . '/' . $sourceId . '/' . $sku,
+                'resourcePath' => self::RESOURCE_PATH . '/' . $sourceCode . '/' . $sku,
                 'httpMethod' => Request::HTTP_METHOD_GET,
             ],
             'soap' => [
@@ -70,7 +70,7 @@ private function getSourceItemConfiguration(int $sourceId, string $sku)
         ];
         $sourceItemConfiguration = (TESTS_WEB_API_ADAPTER === self::ADAPTER_REST)
             ? $this->_webApiCall($serviceInfo)
-            : $this->_webApiCall($serviceInfo, ['sourceId' => $sourceId, 'sku' => $sku]);
+            : $this->_webApiCall($serviceInfo, ['sourceCode' => $sourceCode, 'sku' => $sku]);
 
         self::assertInternalType('array', $sourceItemConfiguration);
         self::assertNotEmpty($sourceItemConfiguration);
diff --git a/app/code/Magento/InventoryConfigurationApi/Test/Api/GetSourceItemConfigurationTest.php b/app/code/Magento/InventoryConfigurationApi/Test/Api/GetSourceItemConfigurationTest.php
index fbefcbdb4284..cf435ba9f47a 100644
--- a/app/code/Magento/InventoryConfigurationApi/Test/Api/GetSourceItemConfigurationTest.php
+++ b/app/code/Magento/InventoryConfigurationApi/Test/Api/GetSourceItemConfigurationTest.php
@@ -23,12 +23,12 @@ class GetSourceItemConfigurationTest extends WebapiAbstract
      */
     public function testGetSourceItemConfiguration()
     {
-        $sourceId = 10;
+        $sourceCode = 'eu-1';
         $sku = 'SKU-1';
 
         $serviceInfo = [
             'rest' => [
-                'resourcePath' => self::RESOURCE_PATH . '/' . $sourceId . '/' . $sku,
+                'resourcePath' => self::RESOURCE_PATH . '/' . $sourceCode . '/' . $sku,
                 'httpMethod' => Request::HTTP_METHOD_GET,
             ],
             'soap' => [
@@ -39,12 +39,12 @@ public function testGetSourceItemConfiguration()
 
         $sourceItemConfiguration = (TESTS_WEB_API_ADAPTER === self::ADAPTER_REST)
             ? $this->_webApiCall($serviceInfo)
-            : $this->_webApiCall($serviceInfo, ['sourceId' => $sourceId, 'sku' => $sku]);
+            : $this->_webApiCall($serviceInfo, ['sourceCode' => $sourceCode, 'sku' => $sku]);
 
         self::assertInternalType('array', $sourceItemConfiguration);
         self::assertNotEmpty($sourceItemConfiguration);
 
-        self::assertEquals($sourceId, $sourceItemConfiguration[SourceItemConfigurationInterface::SOURCE_ID]);
+        self::assertEquals($sourceCode, $sourceItemConfiguration[SourceItemConfigurationInterface::SOURCE_CODE]);
         self::assertEquals($sku, $sourceItemConfiguration[SourceItemConfigurationInterface::SKU]);
         self::assertEquals(2, $sourceItemConfiguration[SourceItemConfigurationInterface::INVENTORY_NOTIFY_QTY]);
     }
diff --git a/app/code/Magento/InventoryConfigurationApi/Test/Api/SourceItemConfigurationsSaveTest.php b/app/code/Magento/InventoryConfigurationApi/Test/Api/SourceItemConfigurationsSaveTest.php
index 829b2a5dc892..052c3710b138 100644
--- a/app/code/Magento/InventoryConfigurationApi/Test/Api/SourceItemConfigurationsSaveTest.php
+++ b/app/code/Magento/InventoryConfigurationApi/Test/Api/SourceItemConfigurationsSaveTest.php
@@ -25,12 +25,12 @@ public function testSaveSourceItemConfiguration()
     {
         $sourceItemConfigurations = [
             [
-                SourceItemConfigurationInterface::SOURCE_ID => 10,
+                SourceItemConfigurationInterface::SOURCE_CODE => 'eu-1',
                 SourceItemConfigurationInterface::SKU => 'SKU-1',
                 SourceItemConfigurationInterface::INVENTORY_NOTIFY_QTY => 2,
             ],
             [
-                SourceItemConfigurationInterface::SOURCE_ID => 20,
+                SourceItemConfigurationInterface::SOURCE_CODE => 'eu-2',
                 SourceItemConfigurationInterface::SKU => 'SKU-1',
                 SourceItemConfigurationInterface::INVENTORY_NOTIFY_QTY => 1,
             ]
@@ -49,23 +49,23 @@ public function testSaveSourceItemConfiguration()
 
         $this->_webApiCall($serviceInfo, ['sourceItemConfigurations' => $sourceItemConfigurations]);
 
-        $sourceItemConfiguration = $this->getSourceItemConfiguration(10, 'SKU-1');
+        $sourceItemConfiguration = $this->getSourceItemConfiguration('eu-1', 'SKU-1');
         self::assertEquals($sourceItemConfigurations[0], $sourceItemConfiguration);
 
-        $sourceItemConfiguration = $this->getSourceItemConfiguration(20, 'SKU-1');
+        $sourceItemConfiguration = $this->getSourceItemConfiguration('eu-2', 'SKU-1');
         self::assertEquals($sourceItemConfigurations[1], $sourceItemConfiguration);
     }
 
     /**
-     * @param int $sourceId
+     * @param string $sourceCode
      * @param string $sku
      * @return array
      */
-    private function getSourceItemConfiguration(int $sourceId, string $sku)
+    private function getSourceItemConfiguration(string $sourceCode, string $sku)
     {
         $serviceInfo = [
             'rest' => [
-                'resourcePath' => self::RESOURCE_PATH . '/' . $sourceId . '/' . $sku,
+                'resourcePath' => self::RESOURCE_PATH . '/' . $sourceCode . '/' . $sku,
                 'httpMethod' => Request::HTTP_METHOD_GET,
             ],
             'soap' => [
@@ -75,7 +75,7 @@ private function getSourceItemConfiguration(int $sourceId, string $sku)
         ];
         $sourceItemConfiguration = (TESTS_WEB_API_ADAPTER === self::ADAPTER_REST)
             ? $this->_webApiCall($serviceInfo)
-            : $this->_webApiCall($serviceInfo, ['sourceId' => $sourceId, 'sku' => $sku]);
+            : $this->_webApiCall($serviceInfo, ['sourceCode' => $sourceCode, 'sku' => $sku]);
 
         self::assertInternalType('array', $sourceItemConfiguration);
         self::assertNotEmpty($sourceItemConfiguration);
diff --git a/app/code/Magento/InventoryConfigurationApi/Test/_files/source_item_configuration.php b/app/code/Magento/InventoryConfigurationApi/Test/_files/source_item_configuration.php
index bcba42fd859a..a8c1323ab65e 100644
--- a/app/code/Magento/InventoryConfigurationApi/Test/_files/source_item_configuration.php
+++ b/app/code/Magento/InventoryConfigurationApi/Test/_files/source_item_configuration.php
@@ -19,7 +19,7 @@
 $sourceItemConfigurationsSave = Bootstrap::getObjectManager()->get(SourceItemConfigurationsSaveInterface::class);
 
 $inventoryConfigurationData = [
-    SourceItemConfigurationInterface::SOURCE_ID => 10,
+    SourceItemConfigurationInterface::SOURCE_CODE => 'eu-1',
     SourceItemConfigurationInterface::SKU => 'SKU-1',
     SourceItemConfigurationInterface::INVENTORY_NOTIFY_QTY => 2.000,
 ];
diff --git a/app/code/Magento/InventoryConfigurationApi/Test/_files/source_item_configuration_rollback.php b/app/code/Magento/InventoryConfigurationApi/Test/_files/source_item_configuration_rollback.php
index 3aa00b1ee1a7..9f82525eefe4 100644
--- a/app/code/Magento/InventoryConfigurationApi/Test/_files/source_item_configuration_rollback.php
+++ b/app/code/Magento/InventoryConfigurationApi/Test/_files/source_item_configuration_rollback.php
@@ -10,4 +10,4 @@
 
 /** @var DeleteSourceItemConfigurationInterface $deleteSourceItemConfiguration */
 $deleteSourceItemConfiguration = Bootstrap::getObjectManager()->get(DeleteSourceItemConfigurationInterface::class);
-$deleteSourceItemConfiguration->execute(10, 'SKU-1');
+$deleteSourceItemConfiguration->execute('eu-1', 'SKU-1');
diff --git a/app/code/Magento/InventoryConfigurationApi/etc/webapi.xml b/app/code/Magento/InventoryConfigurationApi/etc/webapi.xml
index d287ef707c65..a0b0b2cf22ff 100644
--- a/app/code/Magento/InventoryConfigurationApi/etc/webapi.xml
+++ b/app/code/Magento/InventoryConfigurationApi/etc/webapi.xml
@@ -6,7 +6,7 @@
 -->
 <routes xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:noNamespaceSchemaLocation="urn:magento:module:Magento_Webapi:etc/webapi.xsd">
-    <route url="/V1/inventory/source-item-configuration/:sourceId/:sku" method="GET">
+    <route url="/V1/inventory/source-item-configuration/:sourceCode/:sku" method="GET">
         <service class="Magento\InventoryConfigurationApi\Api\GetSourceItemConfigurationInterface" method="execute"/>
         <resources>
             <resource ref="Magento_InventoryApi::source"/>
diff --git a/app/code/Magento/InventoryImportExport/Files/Sample/stock_sources.csv b/app/code/Magento/InventoryImportExport/Files/Sample/stock_sources.csv
index 7d1852724546..501a49953883 100644
--- a/app/code/Magento/InventoryImportExport/Files/Sample/stock_sources.csv
+++ b/app/code/Magento/InventoryImportExport/Files/Sample/stock_sources.csv
@@ -1,5 +1,5 @@
-source_id,sku,status,quantity
-1,sku1,1,10
-2,sku2,1,10
-3,sku3,1,10
-4,sku4,1,15
+source_code,sku,status,quantity
+default,sku1,1,10.10
+default,sku2,1,10.55
+source-1,sku3,1,10
+source-2,sku4,1,15
diff --git a/app/code/Magento/InventoryImportExport/Model/Export/AttributeCollectionProvider.php b/app/code/Magento/InventoryImportExport/Model/Export/AttributeCollectionProvider.php
index 822d8c674bbf..d4177ac20b91 100644
--- a/app/code/Magento/InventoryImportExport/Model/Export/AttributeCollectionProvider.php
+++ b/app/code/Magento/InventoryImportExport/Model/Export/AttributeCollectionProvider.php
@@ -48,13 +48,13 @@ public function __construct(
     public function get(): Collection
     {
         if (count($this->collection) === 0) {
-            /** @var \Magento\Eav\Model\Entity\Attribute $sourceIdAttribute */
-            $sourceIdAttribute = $this->attributeFactory->create();
-            $sourceIdAttribute->setId(SourceItemInterface::SOURCE_ID);
-            $sourceIdAttribute->setDefaultFrontendLabel(SourceItemInterface::SOURCE_ID);
-            $sourceIdAttribute->setAttributeCode(SourceItemInterface::SOURCE_ID);
-            $sourceIdAttribute->setBackendType('int');
-            $this->collection->addItem($sourceIdAttribute);
+            /** @var \Magento\Eav\Model\Entity\Attribute $sourceCodeAttribute */
+            $sourceCodeAttribute = $this->attributeFactory->create();
+            $sourceCodeAttribute->setId(SourceItemInterface::SOURCE_CODE);
+            $sourceCodeAttribute->setDefaultFrontendLabel(SourceItemInterface::SOURCE_CODE);
+            $sourceCodeAttribute->setAttributeCode(SourceItemInterface::SOURCE_CODE);
+            $sourceCodeAttribute->setBackendType('varchar');
+            $this->collection->addItem($sourceCodeAttribute);
 
             /** @var \Magento\Eav\Model\Entity\Attribute $skuAttribute */
             $skuAttribute = $this->attributeFactory->create();
diff --git a/app/code/Magento/InventoryImportExport/Model/Export/ColumnProvider.php b/app/code/Magento/InventoryImportExport/Model/Export/ColumnProvider.php
index 338dcde9b6b4..592886090dc3 100644
--- a/app/code/Magento/InventoryImportExport/Model/Export/ColumnProvider.php
+++ b/app/code/Magento/InventoryImportExport/Model/Export/ColumnProvider.php
@@ -8,8 +8,8 @@
 namespace Magento\InventoryImportExport\Model\Export;
 
 use Magento\Framework\Data\Collection as AttributeCollection;
-use Magento\InventoryImportExport\Model\Export\ColumnProviderInterface;
 use Magento\ImportExport\Model\Export;
+use \Magento\Framework\Exception\LocalizedException;
 
 /**
  * @inheritdoc
@@ -30,6 +30,10 @@ public function getHeaders(AttributeCollection $attributeCollection, array $filt
             return $columns;
         }
 
+        if (count($filters[Export::FILTER_ELEMENT_SKIP]) === count($columns)) {
+            throw new LocalizedException(__('There is no data for the export.'));
+        }
+
         // remove the skipped from columns
         $skippedAttributes = array_flip($filters[Export::FILTER_ELEMENT_SKIP]);
         foreach ($columns as $key => $value) {
diff --git a/app/code/Magento/InventoryImportExport/Model/Export/SourceItemCollectionFactory.php b/app/code/Magento/InventoryImportExport/Model/Export/SourceItemCollectionFactory.php
index c27e830a47f5..c1e22e044bf5 100644
--- a/app/code/Magento/InventoryImportExport/Model/Export/SourceItemCollectionFactory.php
+++ b/app/code/Magento/InventoryImportExport/Model/Export/SourceItemCollectionFactory.php
@@ -7,10 +7,14 @@
 
 namespace Magento\InventoryImportExport\Model\Export;
 
+use Magento\Framework\App\ResourceConnection;
 use Magento\Framework\Data\Collection as AttributeCollection;
 use Magento\Framework\Exception\LocalizedException;
 use Magento\Framework\ObjectManagerInterface;
+use Magento\Inventory\Model\ResourceModel\Source as SourceResourceModel;
 use Magento\Inventory\Model\ResourceModel\SourceItem\Collection;
+use Magento\InventoryApi\Api\Data\SourceInterface;
+use Magento\InventoryApi\Api\Data\SourceItemInterface;
 use Magento\InventoryImportExport\Model\Export\ColumnProviderInterface;
 use Magento\InventoryImportExport\Model\Export\SourceItemCollectionFactoryInterface;
 use Magento\ImportExport\Model\Export;
@@ -20,6 +24,11 @@
  */
 class SourceItemCollectionFactory implements SourceItemCollectionFactoryInterface
 {
+    /**
+     * Source code field name
+     */
+    const SOURCE_CODE_FIELD = 'source_' . SourceInterface::SOURCE_CODE;
+
     /**
      * @var ObjectManagerInterface
      */
@@ -60,7 +69,8 @@ public function create(AttributeCollection $attributeCollection, array $filters)
     {
         /** @var Collection $collection */
         $collection = $this->objectManager->create(Collection::class);
-        $collection->addFieldToSelect($this->columnProvider->getColumns($attributeCollection, $filters));
+        $columns = $this->columnProvider->getColumns($attributeCollection, $filters);
+        $collection->addFieldToSelect($columns);
 
         foreach ($this->retrieveFilterData($filters) as $columnName => $value) {
             $attributeDefinition = $attributeCollection->getItemById($columnName);
@@ -81,7 +91,6 @@ public function create(AttributeCollection $attributeCollection, array $filters)
 
             $this->filterProcessor->process($type, $collection, $columnName, $value);
         }
-
         return $collection;
     }
 
diff --git a/app/code/Magento/InventoryImportExport/Model/Import/Command/Replace.php b/app/code/Magento/InventoryImportExport/Model/Import/Command/Replace.php
index 17131d140009..45289121a89b 100644
--- a/app/code/Magento/InventoryImportExport/Model/Import/Command/Replace.php
+++ b/app/code/Magento/InventoryImportExport/Model/Import/Command/Replace.php
@@ -49,7 +49,7 @@ public function __construct(
     /**
      * {@inheritdoc}
      *
-     * If an SKU and SOURCE_ID in the import data matches the SKU and SOURCE_ID of an existing entity,
+     * If an SKU and SOURCE_CODE in the import data matches the SKU and SOURCE_CODE of an existing entity,
      * all fields are deleted and new a record is created.
      */
     public function execute(array $bunch)
diff --git a/app/code/Magento/InventoryImportExport/Model/Import/SourceItemConvert.php b/app/code/Magento/InventoryImportExport/Model/Import/SourceItemConvert.php
old mode 100644
new mode 100755
index b00bbd23a80b..4e918c842f3a
--- a/app/code/Magento/InventoryImportExport/Model/Import/SourceItemConvert.php
+++ b/app/code/Magento/InventoryImportExport/Model/Import/SourceItemConvert.php
@@ -36,7 +36,7 @@ public function convert(array $bunch): array
         foreach ($bunch as $rowData) {
             /** @var SourceItemInterface $sourceItem */
             $sourceItem = $this->sourceItemFactory->create();
-            $sourceItem->setSourceId($rowData[Sources::COL_SOURCE]);
+            $sourceItem->setSourceCode($rowData[Sources::COL_SOURCE_CODE]);
             $sourceItem->setSku($rowData[Sources::COL_SKU]);
             $sourceItem->setQuantity($rowData[Sources::COL_QTY]);
 
diff --git a/app/code/Magento/InventoryImportExport/Model/Import/Sources.php b/app/code/Magento/InventoryImportExport/Model/Import/Sources.php
index 5e46a8e35d25..2b75b15f106c 100644
--- a/app/code/Magento/InventoryImportExport/Model/Import/Sources.php
+++ b/app/code/Magento/InventoryImportExport/Model/Import/Sources.php
@@ -27,7 +27,7 @@ class Sources extends AbstractEntity
      * Column names for import file
      */
     const COL_SKU = SourceItemInterface::SKU;
-    const COL_SOURCE = SourceItemInterface::SOURCE_ID;
+    const COL_SOURCE_CODE = SourceItemInterface::SOURCE_CODE;
     const COL_QTY = SourceItemInterface::QUANTITY;
     const COL_STATUS = SourceItemInterface::STATUS;
 
diff --git a/app/code/Magento/InventoryImportExport/Model/Import/Validator/SourceValidator.php b/app/code/Magento/InventoryImportExport/Model/Import/Validator/SourceValidator.php
index 94e6f3b8c9fb..d65c97817a6b 100644
--- a/app/code/Magento/InventoryImportExport/Model/Import/Validator/SourceValidator.php
+++ b/app/code/Magento/InventoryImportExport/Model/Import/Validator/SourceValidator.php
@@ -29,7 +29,7 @@ class SourceValidator implements ValidatorInterface
     /**
      * @var array
      */
-    private $sourceIds = [];
+    private $sourceCodes = [];
 
     /**
      * @param ValidationResultFactory $validationResultFactory
@@ -41,7 +41,7 @@ public function __construct(
     ) {
         $this->validationResultFactory = $validationResultFactory;
         $this->sourceRepository = $sourceRepository;
-        $this->loadSourceIds();
+        $this->loadSourceCodes();
     }
 
     /**
@@ -51,10 +51,10 @@ public function validate(array $rowData, int $rowNumber)
     {
         $errors = [];
 
-        if (!isset($rowData[Sources::COL_SOURCE])) {
-            $errors[] = __('Missing required column "%column"', ['column' => Sources::COL_SOURCE]);
-        } elseif (!$this->isExistingSource($rowData[Sources::COL_SOURCE])) {
-            $errors[] = __('Source id "%id" does not exists', ['id' => $rowData[Sources::COL_SOURCE]]);
+        if (!isset($rowData[Sources::COL_SOURCE_CODE])) {
+            $errors[] = __('Missing required column "%column"', ['column' => Sources::COL_SOURCE_CODE]);
+        } elseif (!$this->isExistingSource($rowData[Sources::COL_SOURCE_CODE])) {
+            $errors[] = __('Source code "%code" does not exists', ['code' => $rowData[Sources::COL_SOURCE_CODE]]);
         }
 
         return $this->validationResultFactory->create(['errors' => $errors]);
@@ -63,25 +63,25 @@ public function validate(array $rowData, int $rowNumber)
     /**
      * Returns exits already the source in sources.
      *
-     * @param int $sourceId
+     * @param string $sourceCode
      * @return bool
      */
-    private function isExistingSource($sourceId): bool
+    private function isExistingSource($sourceCode): bool
     {
-        return isset($this->sourceIds[$sourceId]);
+        return isset($this->sourceCodes[$sourceCode]);
     }
 
     /**
-     * Loads all existing source ids
+     * Loads all existing source codes
      *
      * @return void
      */
-    private function loadSourceIds()
+    private function loadSourceCodes()
     {
         $sources = $this->sourceRepository->getList();
         foreach ($sources->getItems() as $source) {
-            $sourceId = $source->getSourceId();
-            $this->sourceIds[$sourceId] = $sourceId;
+            $sourceCode = $source->getSourceCode();
+            $this->sourceCodes[$sourceCode] = $sourceCode;
         }
     }
 }
diff --git a/app/code/Magento/InventoryImportExport/Model/StockItemImporter.php b/app/code/Magento/InventoryImportExport/Model/StockItemImporter.php
old mode 100644
new mode 100755
index 2bd49881f24a..26eb01aa8caf
--- a/app/code/Magento/InventoryImportExport/Model/StockItemImporter.php
+++ b/app/code/Magento/InventoryImportExport/Model/StockItemImporter.php
@@ -10,6 +10,7 @@
 use Magento\CatalogImportExport\Model\StockItemImporterInterface;
 use Magento\CatalogImportExport\Model\Import\Product;
 use Magento\Inventory\Model\SourceItemFactory;
+use Magento\InventoryApi\Api\Data\SourceItemInterface;
 use Magento\InventoryApi\Api\SourceItemsSaveInterface;
 use Magento\InventoryCatalog\Api\DefaultSourceProviderInterface;
 
@@ -66,9 +67,10 @@ public function import(array $stockData)
             if (isset($stockDatum[Product::COL_SKU])) {
                 $inStock = (isset($stockDatum['is_in_stock'])) ? $stockDatum['is_in_stock'] : 0;
                 $qty = (isset($stockDatum['qty'])) ? $stockDatum['qty'] : 0;
+                /** @var SourceItemInterface $sourceItem */
                 $sourceItem = $this->sourceItemFactory->create();
                 $sourceItem->setSku($stockDatum[Product::COL_SKU]);
-                $sourceItem->setSourceId($this->defaultSource->getId());
+                $sourceItem->setSourceCode($this->defaultSource->getCode());
                 $sourceItem->setQuantity($qty);
                 $sourceItem->setStatus($inStock);
                 $sourceItems[] = $sourceItem;
diff --git a/app/code/Magento/InventoryImportExport/Test/Integration/Model/Export/SourcesTest.php b/app/code/Magento/InventoryImportExport/Test/Integration/Model/Export/SourcesTest.php
index 485705f22b89..77693884cddc 100644
--- a/app/code/Magento/InventoryImportExport/Test/Integration/Model/Export/SourcesTest.php
+++ b/app/code/Magento/InventoryImportExport/Test/Integration/Model/Export/SourcesTest.php
@@ -121,10 +121,7 @@ public function testExportWithSourceFilter()
     {
         $this->exporter->setParameters([
             Export::FILTER_ELEMENT_GROUP => [
-                'source_id' => [
-                    22,
-                    62
-                ]
+                'source_code' => 'eu'
             ]
         ]);
         $this->exporter->export();
diff --git a/app/code/Magento/InventoryImportExport/Test/Integration/Model/Export/_files/export_filtered_by_sku.csv b/app/code/Magento/InventoryImportExport/Test/Integration/Model/Export/_files/export_filtered_by_sku.csv
index 449aeb78494e..040759777007 100644
--- a/app/code/Magento/InventoryImportExport/Test/Integration/Model/Export/_files/export_filtered_by_sku.csv
+++ b/app/code/Magento/InventoryImportExport/Test/Integration/Model/Export/_files/export_filtered_by_sku.csv
@@ -1,5 +1,5 @@
-source_id,sku,status,quantity
-10,SKU-1,1,5.5000
-20,SKU-1,1,3.0000
-30,SKU-1,0,10.0000
-40,SKU-1,1,10.0000
+source_code,sku,status,quantity
+eu-1,SKU-1,1,5.5000
+eu-2,SKU-1,1,3.0000
+eu-3,SKU-1,0,10.0000
+eu-disabled,SKU-1,1,10.0000
diff --git a/app/code/Magento/InventoryImportExport/Test/Integration/Model/Export/_files/export_filtered_by_source.csv b/app/code/Magento/InventoryImportExport/Test/Integration/Model/Export/_files/export_filtered_by_source.csv
index 752c4c8699a2..5d30c3f9e7a6 100644
--- a/app/code/Magento/InventoryImportExport/Test/Integration/Model/Export/_files/export_filtered_by_source.csv
+++ b/app/code/Magento/InventoryImportExport/Test/Integration/Model/Export/_files/export_filtered_by_source.csv
@@ -1,4 +1,6 @@
-source_id,sku,status,quantity
-30,SKU-1,0,10.0000
-40,SKU-1,1,10.0000
-50,SKU-2,1,5.0000
+source_code,sku,status,quantity
+eu-1,SKU-1,1,5.5000
+eu-2,SKU-1,1,3.0000
+eu-3,SKU-1,0,10.0000
+eu-disabled,SKU-1,1,10.0000
+eu-2,SKU-3,0,6.0000
diff --git a/app/code/Magento/InventoryImportExport/Test/Integration/Model/Export/_files/export_filtered_without_status_column.csv b/app/code/Magento/InventoryImportExport/Test/Integration/Model/Export/_files/export_filtered_without_status_column.csv
index 89cb0643b37c..7a9ec068d744 100644
--- a/app/code/Magento/InventoryImportExport/Test/Integration/Model/Export/_files/export_filtered_without_status_column.csv
+++ b/app/code/Magento/InventoryImportExport/Test/Integration/Model/Export/_files/export_filtered_without_status_column.csv
@@ -1,4 +1,4 @@
-source_id,sku,quantity
-10,SKU-1,5.5000
-20,SKU-1,3.0000
-40,SKU-1,10.0000
+source_code,sku,quantity
+eu-1,SKU-1,5.5000
+eu-2,SKU-1,3.0000
+eu-disabled,SKU-1,10.0000
diff --git a/app/code/Magento/InventoryImportExport/Test/Integration/Model/Export/_files/export_full.csv b/app/code/Magento/InventoryImportExport/Test/Integration/Model/Export/_files/export_full.csv
index aca33a8fff41..0e6d1ed2b358 100644
--- a/app/code/Magento/InventoryImportExport/Test/Integration/Model/Export/_files/export_full.csv
+++ b/app/code/Magento/InventoryImportExport/Test/Integration/Model/Export/_files/export_full.csv
@@ -1,6 +1,6 @@
-source_id,sku,status,quantity
-10,SKU-1,1,5.5000
-20,SKU-1,1,3.0000
-30,SKU-1,0,10.0000
-40,SKU-1,1,10.0000
-50,SKU-2,1,5.0000
+source_code,sku,status,quantity
+eu-1,SKU-1,1,5.5000
+eu-2,SKU-1,1,3.0000
+eu-3,SKU-1,0,10.0000
+eu-disabled,SKU-1,1,10.0000
+us-1,SKU-2,1,5.0000
diff --git a/app/code/Magento/InventoryImportExport/Test/Integration/Model/Import/SourcesTest.php b/app/code/Magento/InventoryImportExport/Test/Integration/Model/Import/SourcesTest.php
old mode 100644
new mode 100755
index 7dd7819e5d16..05aeedc5dc4b
--- a/app/code/Magento/InventoryImportExport/Test/Integration/Model/Import/SourcesTest.php
+++ b/app/code/Magento/InventoryImportExport/Test/Integration/Model/Import/SourcesTest.php
@@ -13,6 +13,7 @@
 use Magento\ImportExport\Model\ResourceModel\Import\Data as ImportData;
 use Magento\InventoryApi\Api\Data\SourceItemInterface;
 use Magento\InventoryApi\Api\SourceItemRepositoryInterface;
+use Magento\InventoryApi\Api\SourceRepositoryInterface;
 use Magento\InventoryImportExport\Model\Import\Sources;
 use Magento\TestFramework\Helper\Bootstrap;
 use PHPUnit\Framework\TestCase;
@@ -29,6 +30,11 @@ class SourcesTest extends TestCase
      */
     private $sourceItemRepository;
 
+    /**
+     * @var SourceRepositoryInterface
+     */
+    private $sourceRepository;
+
     /**
      * @var SearchCriteriaBuilder
      */
@@ -50,6 +56,7 @@ protected function setUp()
         ]);
 
         $this->sourceItemRepository = Bootstrap::getObjectManager()->create(SourceItemRepositoryInterface::class);
+        $this->sourceRepository = Bootstrap::getObjectManager()->create(SourceRepositoryInterface::class);
         $this->searchCriteriaBuilder = Bootstrap::getObjectManager()->create(SearchCriteriaBuilder::class);
     }
 
@@ -58,7 +65,7 @@ protected function setUp()
      */
     public function testValidateRowExpectsInvalidRow()
     {
-        $rowData = $this->buildRowDataArray(880, 'SKU-55', 33, 1);
+        $rowData = $this->buildRowDataArray('us-2', 'SKU-55', 33, 1);
         $result = $this->importer->validateRow($rowData, 2);
         $this->assertNotTrue($result, 'Expect result FALSE as given source ID is not present in database.');
     }
@@ -68,24 +75,18 @@ public function testValidateRowExpectsInvalidRow()
      */
     public function testValidateRowExpectsValidRow()
     {
-        $rowData = $this->buildRowDataArray(20, 'SKU-55', 33, 1);
+        $rowData = $this->buildRowDataArray('eu-2', 'SKU-55', 33, 1);
         $result = $this->importer->validateRow($rowData, 2);
         $this->assertTrue($result, 'Expect result TRUE as given data is valid.');
     }
 
-    /**
-     * @expectedException \Magento\Framework\Exception\LocalizedException
-     */
     public function testImportDataWithWrongBehavior()
     {
         $this->importer->setParameters([
             'behavior' => 'WrongBehavior'
         ]);
 
-        $bunch = [
-            $this->buildRowDataArray(10, 'SKU-1', 6.88, 1)
-        ];
-        $this->importData($bunch);
+        $this->assertEquals($this->importer->getBehavior(), \Magento\ImportExport\Model\Import::getDefaultBehavior());
     }
 
     /**
@@ -105,10 +106,10 @@ public function testImportDataWithAppendBehavior()
         $beforeImportData = $this->getSourceItemList($searchCriteria);
 
         $bunch = [
-            $this->buildRowDataArray(10, 'SKU-1', 6.8800, 1),
-            $this->buildRowDataArray(20, 'SKU-1', 5.0000, 1),
-            $this->buildRowDataArray(50, 'SKU-2', 15, 1),
-            $this->buildRowDataArray(10, 'SKU-2', 33, 1),
+            $this->buildRowDataArray('eu-1', 'SKU-1', 6.8800, 1),
+            $this->buildRowDataArray('eu-2', 'SKU-1', 5.0000, 1),
+            $this->buildRowDataArray('us-1', 'SKU-2', 15, 1),
+            $this->buildRowDataArray('eu-1', 'SKU-2', 33, 1),
         ];
         $this->importData($bunch);
 
@@ -134,8 +135,8 @@ public function testImportDataWithDelteBehavior()
         $searchCriteria = $this->searchCriteriaBuilder->create();
 
         $bunch = [
-            $this->buildRowDataArray(10, 'SKU-1', 6.88, 1),
-            $this->buildRowDataArray(20, 'SKU-1', 5, 1),
+            $this->buildRowDataArray('eu-1', 'SKU-1', 6.88, 1),
+            $this->buildRowDataArray('eu-2', 'SKU-1', 5, 1),
         ];
         $this->importData($bunch);
 
@@ -160,16 +161,16 @@ public function testImportDataWithReplaceBehavior()
         ]);
 
         $bunch = [
-            $this->buildRowDataArray(20, 'SKU-1', 5, 1),
-            $this->buildRowDataArray(50, 'SKU-2', 15, 1),
+            $this->buildRowDataArray('eu-2', 'SKU-1', 5, 1),
+            $this->buildRowDataArray('us-1', 'SKU-2', 15, 1),
         ];
         $this->importData($bunch);
 
         $searchCriteria = $this->searchCriteriaBuilder->create();
         $afterImportData = $this->getSourceItemList($searchCriteria);
 
-        $this->assertArrayHasKey('20-SKU-1', $afterImportData);
-        $this->assertArrayHasKey('50-SKU-2', $afterImportData);
+        $this->assertArrayHasKey('eu-2-SKU-1', $afterImportData);
+        $this->assertArrayHasKey('us-1-SKU-2', $afterImportData);
     }
 
     /**
@@ -183,7 +184,7 @@ public function testImportDataWithReplaceBehaviorNoAffectOtherSources()
     {
         $searchCriteria = $this->searchCriteriaBuilder->create();
         $beforeImportData = $this->getSourceItemList($searchCriteria);
-        $this->assertArrayHasKey('10-SKU-1', $beforeImportData);
+        $this->assertArrayHasKey('eu-1-SKU-1', $beforeImportData);
 
         /** @see \Magento\InventoryImportExport\Model\Import\Command\Replace::execute */
         $this->importer->setParameters([
@@ -191,30 +192,30 @@ public function testImportDataWithReplaceBehaviorNoAffectOtherSources()
         ]);
 
         $bunch = [
-            $this->buildRowDataArray(20, 'SKU-1', 20, 1),
-            $this->buildRowDataArray(50, 'SKU-2', 15, 1),
+            $this->buildRowDataArray('eu-2', 'SKU-1', 20, 1),
+            $this->buildRowDataArray('us-1', 'SKU-2', 15, 1),
         ];
         $this->importData($bunch);
         $afterImportData = $this->getSourceItemList($searchCriteria);
 
         // checks whether original source item which has not been imported stays in database
-        $this->assertEquals($beforeImportData['10-SKU-1'], $afterImportData['10-SKU-1']);
+        $this->assertEquals($beforeImportData['eu-1-SKU-1'], $afterImportData['eu-1-SKU-1']);
 
-        $this->assertArrayHasKey('20-SKU-1', $afterImportData);
-        $this->assertArrayHasKey('50-SKU-2', $afterImportData);
+        $this->assertArrayHasKey('eu-2-SKU-1', $afterImportData);
+        $this->assertArrayHasKey('us-1-SKU-2', $afterImportData);
     }
 
     /**
-     * @param int $sourceID
+     * @param string $sourceCode
      * @param string $sku
      * @param int $qty
      * @param int $status
      * @return array
      */
-    private function buildRowDataArray($sourceID, $sku, $qty, $status)
+    private function buildRowDataArray($sourceCode, $sku, $qty, $status)
     {
         return [
-            Sources::COL_SOURCE => $sourceID,
+            Sources::COL_SOURCE_CODE => $sourceCode,
             Sources::COL_SKU => $sku,
             Sources::COL_QTY => $qty,
             Sources::COL_STATUS => $status,
@@ -229,9 +230,9 @@ private function buildDataArray(array $sourceItems)
     {
         $comparableArray = [];
         foreach ($sourceItems as $sourceItem) {
-            $key = sprintf('%s-%s', $sourceItem->getSourceId(), $sourceItem->getSku());
+            $key = sprintf('%s-%s', $sourceItem->getSourceCode(), $sourceItem->getSku());
             $comparableArray[$key] = $this->buildRowDataArray(
-                $sourceItem->getSourceId(),
+                $sourceItem->getSourceCode(),
                 $sourceItem->getSku(),
                 $sourceItem->getQuantity(),
                 $sourceItem->getStatus()
@@ -248,9 +249,9 @@ private function buildDataArray(array $sourceItems)
     private function updateDataArrayByBunch(array $data, array $bunch)
     {
         foreach ($bunch as $bunchData) {
-            $key = sprintf('%s-%s', $bunchData[Sources::COL_SOURCE], $bunchData[Sources::COL_SKU]);
+            $key = sprintf('%s-%s', $bunchData[Sources::COL_SOURCE_CODE], $bunchData[Sources::COL_SKU]);
             $data[$key] = $this->buildRowDataArray(
-                $bunchData[Sources::COL_SOURCE],
+                $bunchData[Sources::COL_SOURCE_CODE],
                 $bunchData[Sources::COL_SKU],
                 number_format($bunchData[Sources::COL_QTY], 4),
                 $bunchData[Sources::COL_STATUS]
diff --git a/app/code/Magento/InventoryImportExport/Test/Integration/Model/StockItemImporterTest.php b/app/code/Magento/InventoryImportExport/Test/Integration/Model/StockItemImporterTest.php
old mode 100644
new mode 100755
index 562eb0b00789..12fb3d704c6c
--- a/app/code/Magento/InventoryImportExport/Test/Integration/Model/StockItemImporterTest.php
+++ b/app/code/Magento/InventoryImportExport/Test/Integration/Model/StockItemImporterTest.php
@@ -78,8 +78,8 @@ public function testSourceItemImportWithDefaultSource()
         $expectedData = [
             SourceItemInterface::SKU => $stockData['sku'],
             SourceItemInterface::QUANTITY => '1.0000',
-            SourceItemInterface::SOURCE_ID => (string) $this->defaultSourceProvider->getId(),
-            SourceItemInterface::STATUS => (string) SourceItemInterface::STATUS_IN_STOCK
+            SourceItemInterface::SOURCE_CODE => (string)$this->defaultSourceProvider->getCode(),
+            SourceItemInterface::STATUS => (string)SourceItemInterface::STATUS_IN_STOCK
         ];
 
         $this->assertArrayHasKey('SKU-1', $compareData);
@@ -102,8 +102,8 @@ private function getSourceItemList()
         );
 
         $searchCriteriaBuilder->addFilter(
-            SourceItemInterface::SOURCE_ID,
-            $this->defaultSourceProvider->getId()
+            SourceItemInterface::SOURCE_CODE,
+            $this->defaultSourceProvider->getCode()
         );
 
         /** @var SearchCriteria $searchCriteria */
@@ -122,7 +122,7 @@ private function buildDataArray(array $sourceItems)
             $comparableArray[$sourceItem->getSku()] = [
                 SourceItemInterface::SKU => $sourceItem->getSku(),
                 SourceItemInterface::QUANTITY => $sourceItem->getQuantity(),
-                SourceItemInterface::SOURCE_ID => $sourceItem->getSourceId(),
+                SourceItemInterface::SOURCE_CODE => $sourceItem->getSourceCode(),
                 SourceItemInterface::STATUS => $sourceItem->getStatus()
             ];
         }
diff --git a/app/code/Magento/InventorySales/Block/Adminhtml/Order/View/Tab/Sources.php b/app/code/Magento/InventorySales/Block/Adminhtml/Order/View/Tab/Sources.php
old mode 100644
new mode 100755
index 2f2f922aaef0..2457eb77f2b2
--- a/app/code/Magento/InventorySales/Block/Adminhtml/Order/View/Tab/Sources.php
+++ b/app/code/Magento/InventorySales/Block/Adminhtml/Order/View/Tab/Sources.php
@@ -80,7 +80,7 @@ public function getSourceItemsData()
             $sourceItems = $this->getSourceItemsBySku($orderItem->getSku());
 
             foreach ($sourceItems as $sourceItem) {
-                $sourceName = $this->sourceRepository->get((int)$sourceItem->getSourceId())->getName();
+                $sourceName = $this->sourceRepository->get($sourceItem->getSourceCode())->getName();
                 $sourceItemsData[$sourceName][] = [
                     'sku' => $sourceItem->getSku(),
                     'qty' => $sourceItem->getQuantity(),
diff --git a/app/code/Magento/InventorySalesApi/Test/Api/StockRepository/SalesChannelManagementTest.php b/app/code/Magento/InventorySalesApi/Test/Api/StockRepository/SalesChannelManagementTest.php
index 7fc70b76406c..793aa56c8337 100644
--- a/app/code/Magento/InventorySalesApi/Test/Api/StockRepository/SalesChannelManagementTest.php
+++ b/app/code/Magento/InventorySalesApi/Test/Api/StockRepository/SalesChannelManagementTest.php
@@ -90,11 +90,11 @@ public function updateStockWithSalesChannelsReplacingDataProvider(): array
                 [
                     [
                         SalesChannelInterface::TYPE => SalesChannelInterface::TYPE_WEBSITE,
-                        SalesChannelInterface::CODE => 'us_website',
+                        SalesChannelInterface::CODE => 'global_website',
                     ],
                     [
                         SalesChannelInterface::TYPE => SalesChannelInterface::TYPE_WEBSITE,
-                        SalesChannelInterface::CODE => 'global_website',
+                        SalesChannelInterface::CODE => 'us_website',
                     ],
                 ],
             ],
diff --git a/dev/tests/integration/testsuite/Magento/CatalogInventory/Model/StockItemSave/StockItemDataChecker.php b/dev/tests/integration/testsuite/Magento/CatalogInventory/Model/StockItemSave/StockItemDataChecker.php
index b489fbdc33b8..5c1ef6462af9 100644
--- a/dev/tests/integration/testsuite/Magento/CatalogInventory/Model/StockItemSave/StockItemDataChecker.php
+++ b/dev/tests/integration/testsuite/Magento/CatalogInventory/Model/StockItemSave/StockItemDataChecker.php
@@ -167,7 +167,7 @@ private function assertArrayContains(array $expected, array $actual)
     private function checkIntegrityWithInventory(Product $product, array $expectedData)
     {
         $searchCriteria = $this->searchCriteriaBuilder
-            ->addFilter(SourceItemInterface::SOURCE_ID, $this->defaultSourceProvider->getId())
+            ->addFilter(SourceItemInterface::SOURCE_CODE, $this->defaultSourceProvider->getCode())
             ->addFilter(SourceItemInterface::SKU, $product->getSku())
             ->create();
         $sourceItems = $this->sourceItemRepository->getList($searchCriteria)->getItems();